I've been trying various Linux flavours every year for 10 years or so. The last year I tried Arch, then EndeavourOS, which has been my most successful Linux exploration I've ever had, and given me huge hope. However, there are still a few things preventing me switching it to my default OS.

I'll put aside Games that need Anti Cheat, as I doubt that will ever be fully fixed, unless Governments force game devs to support more than just Windows.

Here is what doesn't work for me:

1. Streaming services like NowTV. (Works in Windows in browser only)
2. DRM proected VST's for use with Reaper (not via Wine)
3. Roblox (Using Waydroid was not very successful)
4. Office 365 (I like Libreoffice and OnlyOffice but fact is Word and Excel are just required for some stuff)