Background processes almost never really use expensive resources on macOS or Linux. Certainly they can cause symptoms sometimes, but it's typically no worse than extra fan noise.

All the wasted resources on most people's machines are going to a) pixel buffers b) browser tabs c) both.

Almost never. But still sometimes

Also computers should run and not run what you choose. Apple should not be able to for e you to run "services" (for themselves) and apps you cant delete