I believe they improved that quite a while ago. For me (using the desktop app) search returns results from 2021 within about a second or so. Granted, this will probably differ based on the number of messages to comb through and possibly the source (web/app) but it seem to be working really well in my case.

I don’t really use search but I can play around with it to see how it is now. Is there anything specific that bothered you about it I should keep in mind?

I’ve been using Tuta for 8 or so years now and outside some rare technical issues years ago, I’ve been pretty happy with it. I’m also not aware of any drama they’d be involved in so they have that going for them.