Removal of "percentage of revenue" based royalties is probably the big one. Others may cite the open source ISA, but I think royalties is the big deal. See Western Digital's plans for RISCV. Taking a 1.5 to 2 percent "off the top revenue/not-profit skim" away is a big deal.

Edit: Fwiw, I hope the open source ISA has secondary societal benefits. I'm not skeptical, just pragmatic. Follow the money.