Building the kernel is not that hard, as you have kernel-devel which has all the sources.

Yeah. Some myth that it's hard to do is not why we end up with monolithic kernels. Like any case where you find yourself thinking "it doesn't look that hard; I could do that easily", it's either harder than it looks or it's done a certain way for an entirely different reason you haven't figured out.

You should learn that reason.

Here is an alternative Piped link(s):

this excerpt of the interview with Jeremy Soller on RedoxOS

Piped is a privacy-respecting open-source alternative frontend to YouTube.

I'm open-source; check me out at GitHub.

If you don't mind me asking, then how do you know the kernel they use is bloated compared to any other kernel? A vast majority of the device-list stuff is loaded only when that device is detected with kernel modules. You aren't actually running everything from the entire kernel, it just has support for the devices if it does detect them. which is basically the functionality you are asking for, ad-hoc device modules.

Monolithic kernels aren't "bad". That's subjective. Monolithic kernels have measurable and significant performance benefits, over micro kernels. You also gain a massive complexity reduction. Micro kernels, historically, have not been very successful, e.g. Hurd, because that complexity management is extremely difficult. Not impossible, but so far kernel development has favored monolithic kernels not without reason.

If what you say is actually that easy, why wouldn't all distro's just do that during the install, and during updates with their package managers? I believe you could do this in Gentoo, but I don't know if it has measurable benefits beyond what performance tuning for your specific CPU arch would give you. Since none of those devices you aren't running are consuming any resources beyond the storage space of the kernel.