The humor in AVGN episodes age more gracefully, if you liked AVGN as a teenager, you'd most likely still like the show as an adult, if not find more enjoyment out of older episodes than you did back then.
Humor in Nostalgia Critic episodes are funny when you're in that teenage phase, but after you're over it, you don't find them that funny and they seem more insufferable, and then you look at his newer shit and just cringe at how shit they are and the fact that he's still going on.
One guy's sense of humor is that which is pretty funny to a lot of us back then, and still is funny, even more funny to us now (I'm referring to rewatching older episodes), other guy's humor was hilarious to us back then, but now it's cringeworthy and is literally "That phase" shit. It's like liking some edgy artist with some cult following and unironically being in that cult when you were younger, and then losing interest and growing up, only to look back and cringe them and your past self for even liking them, and realizing they were pretty shitty to begin with, just look at a lot of people who were once Jugalos or something retarded like that a decade or two ago, and now just absolutely hate that shit because it literally is just bullshit for edgelords in the "That Phase" agegroup they were in, and yet those bands are still fucking producing music because of course a bunch of people are always getting into "that phase". Sadly this means Nostalgia Critic is never going to end, unless Doug dies, and even then I want to bet he'd just pass the torch before hand, and regardless, the channel awesome culture is too strong. Jimbo say anything he can or wants, but that's not going to stop Doug or the whole Channel Awesome thing in general.