I agree, he was funny on NBC, but when he didn’t get the Tonight Show gig, he went to CBS and was painfully unfunny.
I quit watching 2 months after he moved to CBS.
I remember back in the early ‘90s, A&E reran his shows from the early to mid 1980s period and many of those were cool to watch, with the guests, etc. I agree with the both of you that the last number of years he was on TV he really was not that watchable, basically anti-Republican stuff that was pretty tired.