Android already satisfies the mobile market nicely. Linux on the whole does everything else Windows can’t or won’t do which, let’s be honest, isn’t much. Furthermore, Google will have to worry about compatibility. There’s a Windows version for literally any computer made as long as it’s made around 1992 or beyond. And while they don’t need to worry about supporting ancient machines at all, that’s still an absolute TON of computers and accessories to support. Linux can do it simply because they had a big head start and a bunch of people behind them. Microsoft has had and right now has a ton of resources to do it (plus a bunch of time as well).