No. Sausage Party is Animation but its for adults. Other animation films and shows have adult humor like Frozen and Tangled. You have animation with death and grief like Big Hero 6. Then you have some anime with blood, guts, and gore. You have animation tv shows based off video games like Arcane. Animation is just a way for telling stories. What those stories tell and the content contained, is another thing all together.

no theres a lot of animation for adults, you just have to search them.

I think that's just a stereotype; I feel like animation is one medium where you can really push the boundaries of storytelling, just like with graphic novels! Scavenger Reign is one that I really enjoyed, and think older people would enjoy. Love, Death and Robots is another (Zima Blue ep. is the best)

Maybe at one point it was (many decades ago), but absolutely not any more. Not solely, anyway.

Nah, my great-grandmother, who was over 100 years old, used to watch cartoons and animations movies.

absolutely not, there are some great adult animations and the ones for kids are so often great for adults as well.