The biggest factor is probably streamers which lean more dramedy than a joke every few seconds and overall seem to be better at making 7/10 or 8/10 level shows than true classic. Furthermore they take away comedy talent from the networks, and also means a comedian like Bill Hader, Nathan Fielder or Eric Andre can be doing their own experimental things instead of grinding it on a sitcom. Or another example Seth Rogen hits stopped coming in the movies but instead of converting to TV he was able to build a producer resume.

The political climate affects it a bit but probably less for the already sterilized TV than movies or stand up. I don't think Barney Stinson could happen today and new animations having some of South Park and Family Guy more offensive jokes couldn't happen, the main reason they get away with it now is they were grandfathered in from a previous time. Another factor is we cancelled some comedians taking some talent off the board including ones that were likely going to be very active making shows like Louis and Aziz.

I still like a lot of comedies currently on like Shrinking, Ted Lasso, Ghosts, Night Court, Velma, Harley Quinn, Hacks however the last ones I considered true classics were in late 2010s with Mindy Project, The Good Place and Broad City. I don't have many true top tier dramas that started in 2020s either so I guess it's not that much worse.