It also gives you insight to how talented some of these performers are, versus others. The scene with Bill Hader and John Mulaney just riffing off each other and improving an entire sketch as John writes it is a level of comedy that few people in the world can achieve. Not hyperbole, imo, because I think Bill Hader and John Mulaney are just that good at what they do, especially when they were fresh and coming up with new ideas.
Really, that entire doc showed me that Bill Hader was just the funniest cast member both on screen and in the office.
The table read with Hader, Armisen, and John Malkovich was just so amazing to see. Especially because I know that skit from the actual airing. It makes me think about how legendary it would have been to see the table reads of some of the most classic skits of all time.
I also would have loved to see something like this with some of the SNL greats like Will Ferrell or Conan. I know Conan got his opportunity for Late Night because Lorne Michaels put him up for it specifically because of how much he made everyone laugh around the office. Will Ferrell was apparently always doing long running gags and characters around the the office, as well.