You know, I remember that during the craze of NFT games. You'd see games that have bad graphics but at first has been in demand because of the rewards they give to their player investors. That's the thing for them during that time and the quality was terrible and I don't know if those type of games are still existing nowadays or they've probably already sinked together with the bear market after that craze.
I think we can't even call those things games. They were just static, dumb point and click websites worse than browser games from the beginning of 2000's. These websites you mentioned were developed by scammers who never had legit intentions of creating real games, since those platforms worked on the same concept of Ponzi schemes, where early investors were able to make huge profit in short time intervails, but the ones coming late just lost money, and the demand for the site went to zero right after.
But thinking about old 2000's browser games, I think it could be an idea blockchain gaming developers to try introducing again on the internet. Maybe real time city building games such as Travian, Tribal Wars, Ikariam, Grepolis could work nicely giving players the chance of earning money from it, while also investing money on it to grow their cities and empires through a cryptocurrency. In fact, developers don't even need to create a native token. If they just adopted Bitcoin, it would be great already.