I didn't watch any of the videos, as based on your summary, they must be full of rubbish.
The Flanker series is *by far* the longest ranged air superiority fighter in the word. It doesn't have an equal in that regard (excepting maybe an F-15E with CFTs - and its not really meant to be an air-superiority fighter, its just based on f*king brilliant one F-15C).
Furthermore, in the early-mid 1980s, with the Fulcrum, AA-11 Archer and the HMS, the MiG-29 would probably have been the dominant factor in any air war between 4th generation jetfighters.... and that's not just my opinion, that's the opinion of most of the NATO (including US) aircrew that flew DACT against the old East German Fulcrums after "the wall" came down.
After that, as you said, funding gaps and an emphasis on kinematic warfare over electronic warfare has left them 30 years out of date from the point everyone else migrated from 4th generation (F-14, F-15, F-16, F/A-18 A-D) to 4.5th generation (F/A-18 E/F, EuroFighter, Rafale, Gripen) never mind 5th gen (F-22, F-35).
the part you quoted isnt from the video, just my general takeaway after the decades of soviet pr debunking after the west got data on actual usage. so dont blame the videos.
the 3rd gen and early 4th gen from both sides were all shorter combat range than most people think(without ext tanks). it wasnt until the usaf went huge (overall size) with the f-15 from the threat of the mig-25 propaganda that we saw the sort of air superiority range race and supercruise outcomes.
most fighter mission hours are in the 1 to 2 hr range at non military power, and obviously much shorter when dumping fuel into the afterburner because pulling "cobras" bled all their airspeed.
the ru airforce doctrine has always been centered on throwing quantity at the threat as fast as possible. that goes back to ww2 with the flying coffin lagg-3s and yaks with disposable 20mm cannons. post guns-only dogfighting, they have always focused their designs on getting something up to altitude asap to launch a missile at the theoretical strategic bomber coming at ussr/russia.
the mig-29 followed the mig-21 as part of the hi-lo workhorse, and yes better ir missiles with helmet mount targeting makes it a threat that has to be addressed but the whole point of sparrows, skyflash, amraam and meteor was to never get that close. and while the mig-21 bison ended up as a dogfighter, the original version started as a short range interceptor.
the main point is that the ussr/ru air forces have never tried to match nato air forces when in the theoretical attack (sead/dead) role. their solution was to have a fast missile truck under cover of ecm/jamming/chaff dump longer range missiles at ground targets. certainly not trying to maintain air superiority control in hostile territory while the su-25 ground pounded. the problem being that those missiles were never proven against western systems in actual combat conditions.
the discussion i was replying to was questioning the actual capability of the ru af.
the ru fighters are a threat. they went all-in on IRST with the fulcrum and flanker which gave them a first shot advantage, and in a intercept situation with a full integrated radar network backing them that is fine. but flying an attack role against stealth and data link in hostile territory they needed way better radars in order to not get popped by an amraam from someone they never saw coming.
ru aerospace has presented itself as at parity feature-wise with the west if maybe 2 to 4 years late to the party. those claims have never been proven in actual combat vs a nato peer. while the mig and sukhoi bureaus have done amazing work in pushing performance, the rest of the systems have been a 'trust me bro' situation. look at the moskva air defense during its sinking.
this gets even more daunting as the f-35 crews are starting to play around with tactics. supposedly they are practicing turning off radars and using only the IRST and AR cams to fight/fly vision only. so no warning that something is in the area, no long range aew radar, no doppler just optical. the enemy gets no hint until the rear ir-receiver picks up the sidewinder motor heat.
the west/nato has always been shadowboxing when it comes to estimating peer/near peer threats. so far russia has yet to come close the promise of their pr. [and no i dont buy into absolute us air superiority, we've seen enough operational ready delays and day 1 defective systems not being discovered until years later. but at least we fire these weapons seriously every so often]