I’ve had Steam running under wine but so many of the games that use it run horribly or crash. I also tend to play Steam games via a Steam Link (rarely actually on the computer directly), and the Windows version of Steam under wine just refuses to work in this way.

The Steam Link doesn’t work well with the Mac Steam client either, so even games that have a Mac version tend to be played from Windows.

Rebooting into Windows takes less than a minute these days anyway so it’s not a massive hassle. On my old Mac it would have taken aaaaaages.