It's purely about the money invested in each so far, and the fact that chips take at least three to four years from getting the funding until having something i

It's purely about the money invested in each so far, and the fact that chips take at least three to four years from getting the funding until having something in mass production for sale to the general public. The really serious money started to move into RISC-V core design during 2021. Things available for purchase now were started back in 2018 or so, with much less money. The "frozen" RISC-V base spec was only published to the world from Berkeley University in 2015 (and ratified in 2019) and the first chip you could buy (F310 chip on the HiFive1 board) was in December 2016. That's barely two chip design cycles ago. The company that did it (SiFive) produced their first two chip and boards (one a Linux-capable 1.5 GHz 64 bit quad core) on their first $8m of funding. Now they have several hundred million of funding, but that's recent.