The issue of fabs is completely orthogonal to the instruction set or core designs of a chip. If RISC-V completely took over microcontrollers tomorrow and every

The issue of fabs is completely orthogonal to the instruction set or core designs of a chip. If RISC-V completely took over microcontrollers tomorrow and every new dishwasher, hard drive, and teledildonic device was RISC-V powered it would do nothing to change your life. You won't get cleaner dishes because a microcontroller was executing RISC-V instructions instead of ARM. The open (or closed) nature of a CPU core isn't really changing the dynamics of electronics in general or computing specifically.