RISC V is the first open source Instruction Set Architecture. Everything needed to fab the chip is open source. It is like how Linux dominates the world in enterprise software, RISC V is doing that for chip fabs. ARM is a closed ISA. Making the chips requires paying a royalty to ARM for each chip made. It is a scheme to extract money through manipulation not true competitive innovation or value.
This is like any other market, as soon as an equivalent open source alternative exists, the incumbent extortionist's days are numbered. Its only customer base is from convenience or ignorance.
The one thing Apple has always been really good at is picking dying architecture for their hardware. If Apple uses it, the hardware is practically doomed. (6502/68k/power PC/ARM)