An index fund is a composite of the larger sector its based on. Basically it buys pieces of all the things in that investment bucket weighted to their market share with the goal of matching what that sector is doing as a whole. So for a S&P 500 index fund in the US when you buy an index fund share (or fraction of a share) you are investing in each and every one those 500 companies (Apple, Microsoft, Amazon, Google, Visa, Johnson & Johnson etc etc). So you don't have to care if Johnson & Johnson is being well managed or even understand the industries they operate in because your returns are based on what all 500 of those companies are doing. If the S&P 500 goes up overall you make money, if it goes down you lose money. And the S&P 500 has gone up way more than it has gone down.
Keep in mind that my example didn't only use $1k to get to $750k. There were increases in there as well as a notable timeframe. That said many people work for 40-45 years so that timeframe fits in there and accounts for the 18-25 range which is indeed harder to save during.
The easiest way to start would be to open a target date retirement index fund. These will adjust the risk profile for you and get more conservative as it gets closer to your designated retirement date (when you can less afford risk). Looks like Vanguard now has Canadian target date retirement funds but not a ton information on their website:
https://www.vanguardcanada.ca/institutional/etfs/target-retirement-funds.htm Just call them up - open an account and start putting money into it. Make sure that is a scheduled and automatic thing - not something you have to think about.
Looks like there is even a Canadian specific Bogleheads sister site if you want to
learn more. I'm guessing the posters on there will also be very helpful like the US site although would likely want you to be familiar with
this and
this before asking for opinions and help. My knowledge is pretty US centric (since that is where my $ is) so I don't know how common it is for Canadian companies to offer additional investment opportunities for employees. If so you'll want to look into those. A quick perusal of the Canadian site I linked earlier would seem to indicate an inclination to include a decent amount of US stocks while investing. Whereas someone in the US might to a 75% US stock/25% International stock allocation in Canada it seems like it's split between 'Canada' stocks, 'US' stocks and 'All other' stocks
This might sound like a lot and it might seem a bit daunting at first but if you spend a few hours learning it sticks with you. Financial planning and investing doesn't change nearly as quickly as tech specs so that baseline education will serve you for decades.
As for why people don't do it? I'm not sure but if I had to guess it's because of a couple of reasons:
-It's not flashy or fast. You see headlines of "If you invested $100 in this company you'd be a millionaire after 2 years!" but not "If you had done this consistently for 30 years you'd be a millionaire!". No one wants to wait 30 years. They want to pick a winner NOW
-It takes a little bit of time to get started. People think it's a huge commitment. But let's say the concepts aren't resonating for some reason and it takes you a couple hours a week for 6 months to learn. Out of the next 40-70 years it will benefit you that is a miniscule percentage of time and effort (And, in reality, a Vanguard advisor will likely get you on the right track faster than that so it can still be pretty fast)
-Everyone knows someone who knows someone who made a ton of money fast by doing something else! Most of those stories turn out to be exaggerations or incredible luck that you are unlikely to replicate but sure sounds a lot easier than boring 'ol index funds.