I think if there's an open standard that different organizations can contribute to things will move faster and will be cheaper than having single organization trying to build a new Linux phone from scratch, it is also more reselient with little centralization. Different groups can specialize on different components where they have expertise.

I chose RISCV because it's a open standard, we could build around that ecosystem.

The standard can be updated, having different generations/versions when it's absolutely necessary. But it shouldn't move too fast especially if the interfaces are clearly defined. Phones from 10 years ago are powerful enough it's just that brands create new devices to force people to upgrade.