Our attention spans have shortened so you can't setup jokes over a page or two. You have to do them rapid fire or you risk losing the audience. That's really hard to do well. I think some of Chuck Lorre's shows have been amazing that way.

A lot of people watch TV while on their phones or laptops, and it's difficult to write for that. You have to over-explain stuff or repeat it because part of the audience wasn't paying attention.

We're a lot more sensitive than we used to be. Somebody has to be the foil in a joke. A lot of people don't want to see people the the victim. (When I fall down a manhole, it's a tragedy. When you do it, it's comedy.)

I think some shows confuse funny with randomness. If you have a proper setup, something random can be funny. Just random, not so much.

We also have less in common with each other than we used to. Ages, economics, beliefs, education, likes/dislikes, etc. One group may find a comedy hilarious while other groups are left scratching their heads. Comedies that attract a broad audience are getting harder to do.

Comedy's also harder than it looks. My two cents.