In most cases yes, that's one of the reasons why I like the Gambling Dapp Coins as the earnings come from people that use the product. Only if the entire move-to-earn space switched to earnings coming from advertisement money that comes in it would be sustainable. The problem there is that earnings would be minimal (Like using brave browser) which wouldn't make a difference for those already motivated to walk/run while most of the current userbase would move to the next scheme where they potentially can make money.