And I also played a lot of games and were making money off them, and I still say that "play to earn" is unsustainable. When Diablo III was released, it featured real money auction house for all in-game items, and while some players made a lot of money from it, the majority of the community hated it and it was soon removed.
You really can't make conclusions based on one or a few examples though. Yes, D3s auction house was totally scrapped, and a few other game economies that failed, but at the same time we have the likes of RuneScape whereas their economies are still running decently.
Most of the gamers are not interested in making money from games, in fact they are very much against the trading of gameplay items - if you played WoW, you know how much the community hates gold sellers.
Idk about you mate, but if I quit playing a videogame, I definitely want to sell my items so I at least get something in return for all my time.
Now imagine if Blizzard turned their WoW token into a blockchain token - now there's suddenly an extra huge incentive to run bots, scam people, hack accounts, etc. because there's an easy way to turn in-game money into real money.
Goldfarms and all those hacks/scams have existed on the RuneScape MMORPG since like 10 years ago. And here it is, still alive.
Bitcoin also incentivizes hackers and scammers to steal money off people. But yet here we are totally loving it because the positives heavily outweighs the negatives; same thing with games with more "open" economies.
AAA gaming industry is already making stupid money with their gambling mechanics and lazy-ass $60 releases and extra DLCs, whatever they can make with play-to-earn model just pales in comparison to that. But I believe this model isn't even profitable, because it pushes players away from the game.
Mate if you hate those cashgrabs, then you should actually probably be pushing for NFTs. Because instead of paying for untradable skins, NFTs are actually easily tradable(blockchain fees aside).