I think the quantity has gone way up because there are so many channels but TV is in a golden age with so many series that are better than most movies. If you are cherry-picking shows to watch from the catalog, now is an incredible time to be watching.
It depends on what you mean. The OP was talking about prime time programming on the 3-4 major networks. That's very different from what's being produced on pay channels like HBO or Showtime, or on Netflix. I agree that the high quality stuff is better than 10-20 years ago, where everything was a Friends or Seinfeld ripoff. But I think most of the high quality stuff is on non-major networks these days. Though maybe that's just my perception. I find myself watching less and less stuff on those networks, and more and more on the other networks.