Valve is testing ARM64 support for popular games, sparking speculations about future hardware

Valve is interested in controlling the software they use on their hardware and not being dependent on Microsoft or license costs. They are a for profit business. More games running on their machines help their sales.

RISC-V would be a terrible architecture for them at the moment. There are zero chips available with somewhat competitive performance. The number of commercial games that natively run on it is also small if not zero.