Do you think Eric become an annoying cartoon character the way he was acting?

I just came here to ask about why Eric's character changed so drastically over the course of the show's run. He basically, went from being kind of a normal older brother character to a barely functional unhinged moron. One theory that I read (https://www.reddit.com/r/television/comments/tos2ef/comment/i29xe3u/?utm_source=reddit&utm_medium=web2x&context=3) is that once he graduated from high school and made it to college, he pretty much stopped having his own problems. So Eric just became a side character who didn't have much to do but come in for a joke now and again.

While I agree that Eric DID essentially become a cartoon (as evinced by him 'disguising' himself as. ..a SOFA in one episode), even towards the end, there were episodes and scenes in which he COULD be serious and even intellectual(e.g. bonding with Tommy then having to consider letting other adopting the boy while risking the boy hating him for it).