The ability to stream media from legit paid sources. (Netflix, Comcast, max, disneyplus, prime, I don't know where the list is currently, but anything that bitches about user agent.)

TPM.

The ability to play multiplayer games that rely on anti-cheat ( seriously, make Linux a hit with the fortnite crowd and the upcoming generation will think of windows as boomerware )

The ability to use an HDMI cable at full speed. (It's the leading A/V cable standard and the only one some people understand. )

Then there's the stuff I'm unsure of the current status of but that I know was a problem once upon a time: Online banking, online doctor stuff, encrypted emails from mainstream providers, you know, anything that could qualify as "every day stuff" that works out of the box on windows and yet sometimes requires complicated (for grandma) setup on Linux.