I made the switch about 1.5 years ago and haven't looked back. The only software I use frequently that doesn't have a good enough equivialent available on Linux is photo editing and CAD. Even for CAD, if it is simple enough, I'll do it in Onshape rather than booting up my Windows VM.

By photo editing, do you mean a RAW editor alternative to Lightroom? Darktable, RAWTherapee, DaVinci Resolve, AfterShot Pro, and the unhelpfully named "Art" [1] are all options for that. For something to replace Photoshop, Affinity can be made to run in Wine, and their CEO is open to the idea of a native port.

[1] https://artraweditor.github.io/

I'm learning a bit of CAD currently (mostly for 3d printing) and I've been using onshape. It seems pretty powerful so far and I've not found anything I can't do with it. Can you elaborate a bit on what I'm missing from more advanced desktop CAD applications?

Have you tried Photopea yet? It's practically a clone of Photoshop, even has content-aware fill and magic erase.