On servers: Red Hat -> Debian (with a brief detour through Ubuntu Server for a couple of years).
On desktop: Red Hat -> Ubuntu -> Manjaro.
Switched away from Red Hat around 2004 after RHL was discontinued and split into RHEL and Fedora. You may think Fedora would've been a more obvious choice but it was still new in 2004 while Debian had 10 years under its belt. We also migrated the servers at work to Debian around that time and I had used Debian at school in the '90s so it made a lot of sense to use it at home.
Ubuntu on desktop was a fucking revelation when it came out (on CDs shipped free to your home π) in 2004. Early days Ubuntu was soooo good that I stayed with it until 2020, long after the magic was gone.
I mean I would've probably left eventually anyway given the whole snap and privacy and so on debacles but what really put me off was how it would almost never upgrade cleanly once you've added a bunch of 3rd party repos (which you wanted to do all the time on a desktop PC). Eventually I got so sick of it that I was determined to find a rolling distro where upgrades would never be a problem.
Tried a bunch of them during stay at home during the pandemic and settled on Manjaro + XFCE on the desktop and a fresh install of Debian stable + Docker on the server as a happy medium between "hands off" and "up to date". I'm at a point where I like my Linux machines to just work and to need zero maintenance so I can put the time into other things instead.