Her work on the Gilmore Girls is scripted acting that any actress could do. It isn't HER comedy, it was a role.
I think calling Spy a "comedy of the decade" is inaccurate. Never-the-less, even if you enjoy it, you must admit the comedy is broad and essentially comes down to McCarthy saying "I'm fat, I'm loud, I'm clumsy! That's not how a spy should work!" Its almost identical to her work in The Heat ("I'm fat, I'm loud, I'm clumsy! That's not how a cop should work!") or her work in Tammy ("I'm fat, I'm loud, I'm clumsy! That's not how a robber should work!"). You get the point.
Bridesmaids, while she is certainly the breakout, I don't think she is the reason the movie is as funny as it is. Her comedy in that movie was "I fart and I'm fat."
This isn't revolutionary stuff. Its almost identical to Kevin Hart's work, which is essentially, "I'm black, I'm loud, I'm not good at basketball like a black man ought to be! How funny is that!?!"
They are both represent very broad humor.
Once again, none of that is an indictment on the quality of it. I will certainly agree that McCarthy's broad humor is better than Kevin Hart's. But it is the same comedic sensibility. The comparisons are not inherently unfair.