My idea is that a CPU is just a component and it's useless by itself without considering the rest of the computer system. ARM needs to dip more into standardising the rest of the picture, and the RISC-V guys could also start looking into creating an open computer architecture initiative/group to prevent further fragmentation.
I do worry though that the RISC-V ecosystem could be really torn in two by a big player (Intel?) who adds proprietary extensions and associated software.