Ah, SUSE. I always forget that one.
I just did a preliminary search (at 3am), according to their documentation, OpenSUSE has a 36 month lifespan between major upgrades. That's a decent amount of time - but I'm worried how well their upgrades would work? Often distro's require complete reinstallation when a new version is released.
Graphics drivers etc are no issue as we're talking about servers here, so the no gui, setup once and maintain type) - That and our EPOS/Desktop systems recently got upgraded to ryzen with amd graphics - I don't miss nvidia :P
Now, Debian on the other hand has upto 5 years with their LTS:
That's still no where near the old, now discontinued CentOS 10 year life span, but it's still a fair amount of time with enough time to plan upgrades as usually, our upgrade is renting a newer replacement dedicated server, setting that one up with the new OS and testing etc, then switching the traffic to it and dropping the old one (Mostly this was done because upgrading between CentOS major versions always required a reinstall).
With that said, 36 months is still 3 years. So it's not an overly short time either and could be do-able. But it does feel short, our servers are usually rented on a 2-year minimum term so we get discounts :P
Thus our absolute minimum expected OS installed time is 2.5 years (allowing time for switching), but we tend to try to keep the servers and OS running longer if we can.
From a Desktop point of view, I'd be interested in OpenSUSE. Sadly not so much for a sever at this time.
But, while we're on SUSE, let's not forget SLES. Out of the SUSE's, SLES would probably be the best candidate next to RHEL or CentOS. But we're a small family run retail business and with everything that happened this year, it's probably out of our budget (last time I checked, it was subscription like RHEL?) - Do Novell still own SUSE?
For the most part I'm just dumping my thoughts here - I'm not an expert in SUSE (any of them) so my information could be incorrect or just straight up wrong.
If I'm wrong, please feel free to correct me with the right information and I'll be happy to take another look into SUSE :-).