>maybe Microsoft should just stop using React for the Start menu, that might be a good start.

Agree but again worth pointing out the obvious. I don't think anyone is actually against React per se, as long as M$ could ensure React render all their screens at 120fps with No Jank, 1-2% CPU resources usage, minimal GPU resources, and little memory usage. All that at least 99.99% of the time. Right now it isn't obvious to me this is possible without significant investment.