I think everybody remembers the funny bits, and forgets about the suck. I don't watch SNL much anymore, but there is some funny stuff on it still. And there is some that is bad.
I saw a bunch of bad reviews of the Trump show in the media. I didn't watch live, but watched on the DVR after I had read the reviews. I laughed out loud at several points in the show. The cold open of MSNBC (with no Trump) was pretty darn funny, and took some solid shots at Hillary and Bernie.
I watch very infrequently. One show in particular sticks in my mind. I watched the whole show and it was probably the worst comedy related television I have every watched. It didn’t produce one laugh. It did produce plenty of groan moments and downright insulting moments.
I watched in the old days, and yes there were some bad skits too, so I get your point. The overall shows were far beyond today’s SNL. Laughable skits in the 80s were 75-80%. Laughable skits today are more like 20-25%. The show I mentioned, it was seriously 0.00%.