“Long-term support” does not mean what you think it does
You may think you know what long-term support" means when picking a Linux distribution and version, but judging by the multitude of utterly wrong takes and deeply confused users I come across online, I'm starting to get the feeling that in fact, no, you don't know what it means. KDE's Nate Graham is seeing the same confusion, and has published a blog post going over what LTS really means in the Linux world.
People seem to think that an LTS release means it's going to be more stable, have fewer bugs, and receive support for a certain set period of time. The reality is that only that last one really applies, sort-of. LTS generally means you're going to be using a Linux distribution version where you'll get security fixes and possibly maintenance updates for a set number of years, but you won't be getting updates with new features or other updates that aren't security fixes.
The purpose of an LTS release is to more or less freeze itself and its packages in time, so that users know exactly what they're getting. However, part of being frozen in time means any bugs, crashes, and hardware support are also frozen in time. The end result is that LTS releases will often have wildly outdated package versions, and those outdated package versions will most likely contain a ton of bugs and issues that have long been fixed in subsequent releases - subsequent releases you're not getting, because you're on an LTS release.
LTS releases are fairly stable and reliable as long as you use the most popular software from their included software repositories. So in the circumstances when this stops being the case, I think sometimes people can feel betrayed. They think, I thought this was supposed to be stable! Why didn't anyone fix this bug yet? Where's my long-term support?"
But Debian, Ubuntu, and Kubuntu never promised any level of stability, reliability, or absence of bugs. They promised that the version-locked software in their repos would receive security fixes for a certain number of years. Ubuntu and Kubuntu also offered a certain amount of non-guaranteed best-effort hardware compatibility improvements and non-security bug fixes.
Nate Graham
This causes major problems for upstream developers. People who use an LTS release will be using versions of packages that are out of date and full of bugs that have already been fixed in later versions, but they don't know that, so they end up reporting these old bugs that have been fixed ages ago as if they're new. If you're an LTS user and you experience a persistent bug and subsequent crash in Kwin, you're most likely going to complain at the Kwin developers, even if the Kwin developers have already fixed this bug 18 months ago. Every week there's at least a few developers in my Fedi timeline rolling their eyes at Debian users reporting bugs fixed ages ago and getting mad when told they should complain at Debian developers for not backporting the fix.
So many LTS users seem to think that LTS equals increased stability, fewer bugs, and fewer crashes, but that's just not what LTS is for or what it claims to offer. Sticking to specific (major) versions of packages means not you're not only missing out on new features and changes - which might be desirable for you - but also on bug fixes.
With LTS, as they say, the bugs are also stable.