About 10% of my students have left. All for the UK. Another ~10% have mentioned leaving. Those tend to be the ones with another passport.
Myself, I still have a better deal here than in the UK. There's actually a lot of nasty political Animal Farm style stuff going on in the UK these days anyway. 5 eyes, 6 eyes. No face-sitting websites?
Not being able to leave is the hardest thing. Not being able to have a proper holiday and not being able to visit family is hard. It's been 2 years now.
But I prefer closed borders to open borders at this stage. I'd rather have that kind of lock down.