SA was the first forum I really got involved in and I posted there for years. When I was there I thought it was the pinnacle of comedy; I'd never been exposed to that brand of humor before it, and I thought it was genius.
When I look at SA today it just seems juvenile and try-hard. Really, painfully unfunny.
I think part of it has to do with the stricter moderation; SA in the early 2000s was 4chan before I knew there was a 4chan, and I appreciated the raucous, sometimes offensive humor.
Moreover though I think you're right, SA is still SA. My ideas about what is funny have changed, but SA is still the same.