Maybe I’m missing something, but why don’t they start RISC-V development too?

It’s clear that their completely locked ARM processors will not succeed forever. But the processors and silicon IP they would design for RV would still be theirs and they could licence this to other manufacturers. Also providing good services and customizability is worth a lot.

tutorialspoint is similarly bad, they are mostly SEOed sites. Sometimes also giving wrong or misleading information.