Two mission critical systems I have are still running 20.04 since 22.04 can be unreliable and flakey in certain key areas (which, AFAICT is absolutely not MATE's fault but a problem with the underlying system, for the most part GNOME/GTK reliability problems ).
Don't take me wrong: For normal day-to-day desktop/laptop use, Ubuntu-MATE 22.04 LTS is perfect.
But for the high and strict reliability I need for my dayjob (i.e. I can't afford even a visual glitch), it fails.
I have absolutely no problem running an out-of-date desktop, as long as the underlying system is up to date. That means I can stay on 20.04 until 24.04 comes out.
I try to get used to the thought that I might have to switch to Ubuntu-Studio (KDE based, RT-kernel) on these machines one day, but it is actually too early to decide. Let's hope 24.04 turns out to be a masterpiece 
I will stay on Ubuntu-MATE as long as possible ( 
I really really love this distro )