Animation for adults has been growing slowly in recent decades, yes, but overwhelmingly. At first, adults were reluctant to see “drawings” that seemed like a kid’s thing.
The real problem with animation itself is the difficulty of carrying it out. I suggest a goal to add for 2024: watch one animation production per month. Even if it's a short film. Exercise with that kidult side that we all have inside, to find the part of us that is usually half lost.