Ubuntu LTS has a package called linux-hwe that backports the latest Ubuntu kernel to the last LTS release. I find it's a good compromise between maintaining a mainline kernel and using an ancient one. And since the hwe kernel is provided by Ubuntu and used in its release, it's been tested by thousands of users and updating it is a breeze.

My only complaint is that I wished it went back 2 LTS releases. For example, the current project I'm working on settled on 20.04 and there are no more new hwe kernels being released for it despite the rest of the userland receiving updates.