Play Netflix, etc at 4K.

Play games on GeForce NOW at a higher resolution than 1080p. :-/

Reinstall Candy Crush.

Literally everything easily with much less effort

1. Power management on certain chips is simply better than anything Linux has to offer (AMD Zen+ mobile for instance)
2. Modular driver architecture with drivers that aren't complete jank to manage and install. A lot of people see this as a pain point, but in reality it's not such a bad thing, especially nowadays.
3. This is a given, but as lots of stuff runs on Windows (namely older games), you can only really make stuff for Windows on Windows. So if you need to develop Win32 software, you really have to use Visual Studio for proper development. Mingw cross compile exists, I know, but that's never going to be as good.

Number 3 is keeping me on Windows. I make mods for old games and I need Visual C++. I almost got the compiler to run under Wine but who knows how it would behave if it did run.

Run normal games like fortnite and warzone, and run other games not through steam without needing to install proto tricks and get the right dependencies for every damn game

i tried producing music with linux native daw and plugins via yabridge. pain in my stupid ass.

Double click to install a program

Spy it's users

Photoshop and Lightroom.

Nowadays I'd say driver discovery for virtually any modern hardware you might plug into your computer. You don't even need to visit websites to download installers anymore. Literally plug it in and it will grab whatever is needed for it to work properly. Yes even Nvidia display driver. Even VR headset.

Never had any issues with multi-monitor setups out of the box either. It just works.

I'd also mention disposable Sandbox and virtualization in general. WSL also runs at native speeds.

VBA support is non existant on Linux

Use the map editor for C&C Generals

Oh look, another command & conquer comment from me. How surprising.

The granularity and scale of active directory is a major thing that is keeping linux out of offices, etc...I know you can do a lot with certain tools but nothing comes close as far as I have seen.