Actually, I think RISC-V is even worse than ARM. With ARM, at least you have a quite reliable instruction set on the CPU. With RISC-V, most vendors have their own extensions of the instruction set, which opens a big can of worms: Either you compile all your stuff for your own CPU, or you have a set of executables for each and every vendors flavor of RISC-V commands, or you exclusively use the RISC-V core commands. The first would be only for hardcore geeks, the second would be a nightmare to maintain, and the third would be not really efficient. Either way, it sucks.