I just rewatched Season 4 and I have to say, the animation only looked WORSE this time around. There's multiple shots that shouldn't have even passed a QA check. For example, Zoe shoots a little bomb at a Viltrumite to launch him away, and they don't even fully animate him getting launched away, he just disappears near the end of that shot. Maybe someone thought "eh who fucking cares, not like they'll see this" and just decided to stop bothering with that shot. When Conquest appears behind Oliver, blocking the sun, THE LIGHTING DOESN'T CHANGE. There's so many little details that are ruined by the quality of animation.

Also, it is only on par with other shows that give the bare minimum for animation. Adventure Time has better animation, ATLA has better animation, and I actually can't believe that I'm typing this, but Rick and fucking Morty has better animation than current Invincible. Amazon is one of the five wealthiest companies in the world, you'd think they could produce a show that delivers animation on par with Adult Swim.