I'm not sure I agree about RISC-V. ARM is now indisputably in the same performance ballpark as x86_64 (M1 most obviously but there are others), as is Power, but RISC-V has a ways to go before it can compete on the same turf. It hasn't even really competed with ARM in embedded, despite its advantages there (though it has all but killed the zombie corpse of neo-MIPS).
I do agree that without other processor makers, however, the Power ecosystem is crucially overdependent on IBM policy. This is not a new problem but it hasn't gotten any better with OpenPOWER.
I did not mean to imply that I thought RISC-V was a challenger to x86 and ARM right now. Just that it is accessible to those that want it which can let them make sure software runs on it. Even that, I do not think is really true yet but it seems like it is the direction things are heading.
With POWER, I just do not see the motivation, outside of IBM, for doing any work with it anymore.
I do agree that without other processor makers, however, the Power ecosystem is crucially overdependent on IBM policy. This is not a new problem but it hasn't gotten any better with OpenPOWER.