Do I always need to keep my kernel updated for the best performance in games, or should I stick to the LTS kernel?
In general having the latest updates helps to improve performance. Here is a recent Ubuntu study from Phoronix that demonstrates this: Two Year Ubuntu Linux Performance Comparison For Intel Xeon "Cascade Lake" - Phoronix
That being said, the Kernel is probably not the most important thing to optimize (unless your system is suffering from driver issues, like mine). Having the latest Mesa (or equivalent graphics driver) will probably give you more. Also check out the gamemode module, which is a massive boost to performance when gaming: Gamemode - ArchWiki
I tried the so called “gaming kernels” (LiquorX, and the like) I didn’t have better performance, I had crashes though…
If you have fairly recent hardware, Latest LTS kernels are perfectly fine for gaming (even 5.4 is fine honestly, but it doesn’t have the Steam patches for Proton’s Fsync feature, 5.10 has it), as said you’ll gain performance elsewhere first (storage device, GPU/CPU optimization/overclock, RAM timings, technical things like that), kernel could maybe, with specific tweaks for specific situations, bring a little performance, but there are many things to optimize before that, the kernel in my opinion is the last thing I would worry about.
If there is really something “game changing” (pun intended) regarding a kernel, worth the switch to it, you’ll probably hear about it with articles or forum posts, but this kind of ‘revolution’ is kinda rare.
Agree, unless your setup has pathalogical hardware support issues. For example my laptop has (fake) thermal heating issues that give me significant performance hits because the governor keeps throttling CPU for no reason. Things have been getting better with each successive kernel from 5.4 to 5.11 and Lenovo promised some major changes with 5.12 which should (fingers crossed!) resolved it.
That being said, these things are rare. If your setup works with the LTS kernel, I would just keep it.
If there is really something “game changing” (pun intended)