The biggest thing that has prevented me from switching prod systems to Debian is that the window for updates is fairly small, at around a year. 13 came out Aug 9, 2025, and 12 goes EOL June 10, 2026. Compared to Ubuntu 24.04 coming out in April 2024, and 22.04 goes EOL in May 2027 (a year after 24.04). So Ubuntu covers 2 releases plus a year.
I know a lot of people feel like this isn't a big deal, but even with Ansible it can be hard to get our fleet of a few hundred machines all upgraded in a year window, being already busy. Some of them are easy, of course, but there are some that take significant time and also involve developer work, etc...
Don't get me wrong, I think Debian is great. But in the data center, there's definitely a case for a longer support window, and I like that about Ubuntu. RHEL is even better for that, but it is very nice that Ubuntu free and Ubuntu commercial are the same, but with RHEL there is that split to CentOS being the free one (haven't used RHELs in quite a while, obviously).