More recents episodes make Lisa more unlikable

Lisa has always been the weakest link IMO. Not only the writers (even during the golden years) used her as some sort of self insert. Because of this she is probably one of the most one-dimensional character of the major characters. (She was doomed to be "flanderized" before it was even a thing!)

With that said, in the few and rare cases when she escapes her tired niche, she becomes an interesting subject… or was, I'm not sure modern Simpsons can pull it at all.

With that said, modern Bart is basically an unlikable sociopath.