IMO the early through mid 90s casts surpassed the original not-ready for primetime players.
Everyone is allowed an opinion and people can disagree on things.
One factor that I view as extremely relevant is age when one is first introduced to things. Something that someone sees for the first time when in high school (or perhaps early college) wil likely be viewed as funny throughout their life, while may not have been viewed as funny if the first thime they saw it was as an adult.
I will say, the late Phil Hartman was extremely talented on multiple levels and had his moments. Michael Meyers, while I personally am not overly fond of his comedic style, has accomplished quite a bit. Dennis Miller, as an acquired taste was pretty good and as long as they were in small sample sizes Dana Carver an Kevin Nealon weren't bad. SNL absolutely had worse casts than that, both before and after.
If you're speaking of a little later with Rock, Sandler, Schneider, Spade and Farley, I imagine that I was too old to have been initially introduced to their humor (SNL version, Rock is great in standup) as I know of many who are huge fans of that era, all would have been teens during their run on SNL.
It is somewhat surprising that the show is still on the air and while yes, periodically a breakout star does emerge, (IMHO) the show really hasn't had consistent, quality writing/performing since the initial cast. Unless you were there when it had it's first run, it is difficult to comprehend how big of a deal it was.