Focus stealing prevention exists for two main reasons: One is security, since we need to prevent rogue apps from deceiving users into e.g. typing their password into another window. If apps can silently claim keyboard focus and open their own window over the currently focused one, this enables phishing and other similar attacks. The other...
I really don’t get all this attention to focus prevention. I personally can’t remember the last time I had a window popping up without it being something I want and expect. IMHO It looks like a theorethical attack vector (steal focus right when typing a password), but in practice I’ve never heard of it happening, not even on windows were focus stealing is fully allowed and expected.
If I had any app stealing focus randomly, the app would be nuked out of existance in no time.
I did experience though focus stealing prevention breaking apps (for example the open folder dialog in vscode not appearing in the front). It also breaks some interruptions that I really really want, like the evolution calendar notification window popping up on top of everything telling me I really should be in a meeting right now (and no, a slowly fading notification on the corner of the second screen I’m not looking at right now won’t work)
A big thank you to the authot of grand theft focus for bringing a bit of sanity back.