Who's taking the other side of this trade? Write out the sentence without the passive voice: "Games companies will pay players in 5 years" and "Investors in game companies will pay players" etc.
If you look closely, in many of these examples the people paying are "new players", in which case it's the straightforward pyramid/MLM approach. Herbalife for gamers.
Money comes in through whales paying for rare items and relatively fast progression. This isn't a new idea, as games such as WOW had a gold farming economy. As with WOW, the game developers would have to be continuously adding layers of content to progress though, to keep the economy churning. If they're trading tokens, I would guess they would need some sort of burn mechanism to keep inflation in check. I guess the game would be feeding 3 different machines then, play for pay players, the developers of the game, and a void for tokens to disappear into? The pay for play element would likely be to work to create the items which the whales would buy.
Ponzi scheme? It could be in the sense that early players gain enough power in the game that they're better able to adapt to changing conditions. I don't know much about Axie, but an influx of players during the pandemic drove up the price of the required assets to play. I don't know if there is an element for whales to buy fast progression. From what I have seen, it doesn't look like a fun game. It just looks like work for everyone involved.
Maybe the developers could come up with a way to cap how many players could actually earn, based on factors such as market conditions and income from whales. You earn your spot with the bar of difficulty rising or falling. I suppose this would be sort of like mining Bitcoin, except the players are grinding.
I can see the crypto miners in games being a thing in the future, but at best players will receive a funky hat or a new gun once in a while for their efforts.