Most will end up in an oversupply and price drop feedback cycle, eventually collapsing.
This piece somewhat touches on that point, and the importance to counter that, which is something only a handful of developments have managed, namely exchanges. Now, STP is using PoB to counter supply inflation too.
I expect other developments that have at least some revenue will follow, and that will set the competition higher. That's where MTOs to STPT stakers may add that extra touch of differentiation to piece out a portion of the staking participation.