You are right to think of separating the video uses from peripherals. One thing that can cause confusion is that the new smaller Type C connector used for fast USB 3.2 Gen2 etc. data devices ALSO has been used as a type of video output port. They are using the same connector system, but the electronics is quite different. You do NOT get high-def video on any USB 3.2 system. Now, that is not to say you could not create a peripheral device box that has outputs for USB 3.2, slots for memory cards, and a video output port, too. It just would need at least two different cables to feed from different computer ports.
I ran into this good article about USB 3.2 today.
The Universal Serial Bus (USB) port is perhaps the most commonly used and easily recognizable PC connectivity standard found on modern hardware. But as universal as the rectangular port and its various data transfer standards are, things have changed with the introduction of USB Type-C, which is...
www.onlogic.com
Let me also alert you about power for USB. And I'm not going into the higher-voltage stuff or charging details, just power required by standard USB 3.2 devices. The older USB 2 standard provided power at 5 VDC at a max of 0.5 A per port. That was suitable for a lot of devices, but very few portable hard drives could work within that limit. So for those particular units, two options were on the market. The obvious one was providing with the drive a small dedicated power supply module - a "power brick" or "wall wart" - that plugs into the drive case. The other was to provide with it a special USB2 cable that had TWO type A connectors on one end. You have to plug in BOTH of those connectors on separate host computer sockets to supply up to double the "normal" current capability to the drive. The drive simply cannot operate without that much power. If you try with a normal cable and no wall wart, most units like that will look like they are trying to work, but fail as soon as you try to access data because the platter can't spin up.
The USB 3 standard from its beginning has had an increased current supply spec of max 0.9 A per port. So now it is common to find "laptop portable hard drives" for USB 3 use with only a single USB 3 cable supplied. Those units have been designed with low-power-consumption components and DO work just fine on a USB 3 port with NO added power supply module. Thus they normally do NOT come with a wall wart, nor with a double-headed cable. However, there is a small trap - most are described as "compatible with USB2". What that actually means is that they CAN be connected to a USB2 port and data transfer will work as it should at the lower USB2 rate but ONLY if you can arrange to supply the POWER the unit needs (close to 0.9 A max current), and you can NOT get that from a standard USB2 port! So an alternative power supply means must be arranged.
Onward to USB 3.2 Hubs. I consider using any USB Hub without its own power source extremely limiting, because every device on the Hub must share the power available from a SINGLE host port. So I always look for a Hub that comes with its own power supply module. Then the real issue is how much power from that module? For a first stab, I will ignore "Charging Ports". The USB 3 standard calls for output of 5 VDC at 0.9 A per port max. So you count the number of ports, multiply by 0.9, and that's how many Amps might be the max load for all devices connected to that hub.
Immediately you run into two complications. One is that many power supply modules are rated in Watts, so you need to convert: each output port is 5 VDC at 0.9 A max, and that means 4.5 Watts per port. The other is that many of these power supply modules deliver power to the Hub at 12 VDC, even though the hub must convert that to 5 VDC for its devices. So IF the power module is spec'd at 12 VDC and a number of AMPS, you have to convert that to Watts, also. In fact, trying to compare the power available from the power module to what the Hub needs is most easily done by converting to Watts on both devices, and THEN comparing.
Now comes the third complication. You almost never see a hub supplied with a power module that DOES actually provide the max power in Watts the Hub's devices might require. That is partly because a heavier power supply costs more. But it also uses the fact that, VERY commonly, nobody uses the max power rating (4.5 W) from every output port simultaneously. Some devices (e.g. a simple mouse or keyboard or memory stick) use much less. Many devices are used only briefly. So even when you have many devices plugged into the Hub, you virtually never will need to supply 4.5W for EVERY port simultaneously. So how much do you need? Well, the unlikely max is 4.5 W per port. I would be concerned about a power supply module able to provide only half of that. But 70% of the max is very likely OK.
Next, add in consideration of Charging Ports. Even the simpler ones that don't get into high voltages and power levels DO aim to provide max output current two to four times the 0.9 A (4.5W) rating. If you plan to use some ports for changing items that might need that kind of heavier fast charging, you need to add that into the power supply module requirements. On the other hand, if you never plan to charge anything, it won't matter. For that reason, in doing all this I prefer to work out the needs of the standard data ports first.THEN work out the needs of the charging ports and add that in. Just a final note on Charging Ports. Some of these are dual-use: they can be used for charging only, or for data (and note that any data device may well be charging itself from the power available). SOME Charging Ports are restricted to that use only and can NOT be used for data devices - these typcally are ports designated for higher power outputs for devices being charged. This has an impact on power supply needs that will have been dealt with above. But it also means that these charging-only ports can NOT be counted when you figure out how many ports you need for data devices.
So that is how I go about deciding how many ports (and of which type) are needed in choosing a Hub, and how large the power supply module should be that comes with it. In some cases, buying a larger hub with more ports on it than you think you need is better because the larger unit comes with a heavier-capacity power supply module you DO think you need.
Finally, a note on Gen's and data rates. The first version of USB 3 in now called USB 3.2 Gen1 and can move data up to 5Gb/s. All the hubs I've seen that claim to be for USB 3 systems should handle that well. The USB 3.2 Gen2 spec moves data up to 10 Gb/s, and there are few devices now that can work that fast. More importantly, I am skeptical whether most USB 3 Hubs now can support that Gen2 speed, so if you expect to need that, examine their claims very carefully - I do not remember seeing a Hub that specifically says it works at that speed. For the new Gen2x2 system that can move data up to 20 Gb/s there are NO devices over the 10 Gb/s rate now. But that rate is achieved with slightly different data transfer methods and tighter demands on cables, cable lengths, etc. These ports typically originate in a different port (Type E) on the mobo and thus feed only to a particular Type C socket on the computer case face. I doubt any Hub will support that system in the near future.