They're working on this right now. Niche applications can still do their thing, but there will be standard profiles for e.g. a "Linux class" application processor, or an "ARM Cortex-M*" equivalent micro-controller.
Did a quick search on this, and I believe the Linux portion of this is the responsibility of the "UNIX-Class Platform Specification Task Group" [1]. They seem to be quite active, which I'm reading as a sign things are progressing.
RISC-V International is sometimes really bad at communicating that it's working on these problems. But odds on, they usually are.
Think of it like this: the difficulty of targeting RISC-V increases with the square of the number of variants.
It's a general rule in systems that difficulty and bugs increase exponentially, not linearly, as complexity increases.