The currently-supported version of the distro you're on. It's a cultural difference. People using Windows seem to spend an inordinate amount of effort coddling

The currently-supported version of the distro you're on. It's a cultural difference. People using Windows seem to spend an inordinate amount of effort coddling along ancient installs of Windows 10, presumably because they're such a pain in the backside to set up (I have personally never successfully installed any version of Windows later than 3.11 and got all my devices working, with graphics and networking support a particular problem). People using Linux will just blow away the install and stick on the latest LTS, because it's quick and easy and supported. If you've got a lot of apps to install it is generally possible to script all that, and so you pull the trigger on an install and it's ready to go in ten minutes. One slight counterexample is the situation that Black Magic Design's video software DaVinci Resolve is in, where it's packaged for (and only officially supported on) CentOS 7, which goes EOL next year. However, it turns out it works just fine in CentOS Stream 8, and indeed it can be run on other distros in a Docker container based on CentOS (and of course running it in a container brings other benefits like being able to work with multiple versions on the same computer). In general though, there's more of a "blow it away and reinstall" approach with Linux when a distro is EOL. I know I'm not the only one that takes this a stage further, and just replaces the hard disk when a new LTS comes out, so if anything happens the old stuff isn't "lost".