The only real BR flops have been HyperScape and maybe that Battlefield BR? You do have a bunch of indie BRs that never truly caught on but as far as big budget titles, the BR genre is as teflon as it gets. Hell, look at how well Naraka Bladepoint is doing. That's the last big BR to release and it's crazy popular.
I dig the Extraction Shooter concept but the idea of Bungie making a BR and then switching gears because a game 1/100th the size of Fortnite released, kinda shows you this guy is just making up BS to get clicks.
I think it's a bit unfair to single out indie titles from this discussion when we have games like PUBG, Rocket League, Among Us, Dead by Daylight, Fall Guys, etc. And Naraka Bladepoint is a good point, although, being melee based and the whole... asian asthetic helps differentiate from the competition.
Mind you, I'm not defending Bundie decision of making an extraction shooter. I honestly think that it should have been a new IP. Nonetheless, like you pointed out, sure, there's room for BR but they need an unique "flavour" so that people can be tempted to try it out/stop constantly playing the same BR over and over again AND make a quality product. But I also can't blame them for going for the Extraction shooter genre. Compared to BR, there's less competition and, there's potential there for sucess if they can solve the skill celling "issue".
You'd have to ask yourself...did those titles fail due to quality issues or did they fail because the genre is saturated?
I don't think a studio like Bungie is saying "Well if Islands of Nyne didn't make it, what chance do we have?"
Plus, you'd have to compare that list with other genres like fighting games, racing games, arena shooters etc and see how many failed games those genres produce over the years.
The genre has so much flexibility that I don't think it's really close to being tapped out.
I think you're still missing the point. It's not impossible for a new BR to succeed, Apex Legends is the perfect example of it. The issue here is that it reaches a point where it requires more effort (or if you prefer, risk) to create something that can succeed in a market where there's already big dogs in control. There's a reason why companies love brand loyalty. Epic could have done all the right things (no exclusives bullshit and a store that had the same quality as Steam) but they would still not succeed. Now, if for some imaginable reason was possible to grab your steam library and put it on the Epic store... uhm... I don't know....
Same thing goes for multiplayer games. You already learned the maps, what are the best weapons/equipment, those small tricks... You have a bunch of free or paid content that you like to show off.... You're still getting new content... Why change to a new game that is basically the same thing but visually different and not as robust?
There's a reason why there's a big rush of similar games whenever something new and successful shows up and as time goes on, they stop making those type of games and move on to something different. Hell, I'm genuinely surprised we haven't seen a AAA Vampire Survivors game... on the other hand, wouldn't be surprised if it's a game mode on the next Call of Duty...