Time was SNL was a televised version of the National Lampoon Radio Show (the concept and cast were lifted in total).
Today, it coasts on the legacy of casts that came before it just as “late night talk shows” coast on the legacy of The Tonight Show With Johnny Carson but neither program holds a challenge to that legacy. “It’s funny because it’s supposed to be funny and you hear laughs”.
The original cast mainly came from Chicago's "Second City".