I’ve found game development to a bit like an exponential curve when it comes to effort. It gets harder as you move through the stages of the project because you have to put in increasingly more effort to see, in many ways, increasingly diminishing returns. This is especially true at polish when you can spend days working on something (whether it’s a bug or polish item) that can both be very cool and add a professional level of detail but ONLY if the player notices it.
But there’s also something of a bell curve when it comes to motivation. It’s very easy to motivate yourself at the beginning when all you see is possibility, and relatively easy at the end when you can see the finish line and you have a ton of work behind you. But that point in the middle where you require a lot of motivation and a lot of effort is super hard to get over for many people, just for the reasons you listed and that can drag on for quite a while depending on the size of the project.
As far as animation goes, in my opinion it’s one of two things - the other being sound/music - that’s hard to do as well as everything else. Because when sound and animation are bad, they tend to be noticeably bad. It’s hard to cover for it. And similarly when they’re good, they add a lot to the experience. So I would suggest those are things where - if you don’t have a real interest or the time to learn them - you look for outside resources (Mixamo animation library for example).