I don't think you should conflate motivational recession (which is healthy and normal; almost everyone gets that once every few months) with "burnout". They're two different things.

Motivation fluctuates and that's fine. There's nothing wrong with picking up a new video game. In fact, I think there's something healing about narrative that is especially relevant to creative people. We need to get into a novel or TV serial or '90s JRPG every now and then.

Burnout is something else entirely that I hope you don't experience. It's severe and it sucks. There's a state at which you get too depressed to work and it can last for months. You get sick a lot, feel weak, can't focus or get anything done. It doesn't sound like you've been there, and I hope you never get there. Burnout usually isn't caused by long working hours or even by project failures alone; it usually involves long hours and negative conditions (especially subordination).