I’ve never updated Ubuntu to a new major version without issues. The worst instance of this was not being able to login in to a desktop environment at all.
At least now we have agents to save us. I updated Ubuntu on my laptop today and firefox lost all my browser data. Thankfully Claude was able to pull in the history/cookies/tabs from the previous install and bring them into the snap install.
I don’t think I would have updated today if I didn’t have an agent to clean up whatever eventually broke.