There was just a new release, so nothing that old for now, but by the time the next release comes around this one will be getting long in the tooth, no doubt. Debian isn't for everyone, but if you need the latest version as a native app then you're not any better off with Ubuntu at this point. Debian is stable and secure and you can use flatpaks, appimages, or even snaps if you're feeling nasty to get any apps that you really need to be up to date. That's not what everyone wants, but for those people I'd recommend something like Arch, Fedora, or OpenSUSE, not Ubuntu. Ubuntu has just been neglecting the desktop for a while now, and it shows. They were the best once. Now everyone has passed them.

Debian and Ubuntu LTS are both ~2 year cycles, but Debian has traditionally been better than Ubuntu at picking up security fixes

If you sign up for Ubuntu Pro, they might be as good as Debian, now, but I haven’t checked

If you want faster than that, something other than Debian makes sense

There's also "testing" in between. It's not as stable as - well - "stable", but I didn't have trouble with it.