TL;DR: While the first season of Oregairu was superficial and perfunctory, the second season taught us that using words like superficial and perfunctory makes us sound pretty smart. It took me so long to write this review because I've been reading through the numerous analytical theses of the characters and apparently this show has a deeper meaning than any of us can begin to understand so obviously I'm just too dumb to get it.
I had high hopes for a season 2 of Oregairu. The first season captivated me with it's light-hearted comedy that could be serious when necessary, with some especially memorable moments. After watching season 2, it's hard to believe they are the same anime. I guess it was because the studio switch, but I wouldn't know. What basically happened was the anime became very.... realistic.
To start, the art style changed from a unique, goofy, full-of-character style to, in my opinion, generic. Sure, perhaps the 'quality' of the art went up with a larger budget, but the characters ended up looking uninspired. This is most evident in comparing Yukino's design changes; she lost her ice-cold stare and attitude with it. Even Hachiman's iconic green hair is gone.
As for the story.... dear god I could not care any less. With the majority of anime taking place in some kind of high school setting, there should be something that makes it stand out, whether it be something supernatural or something just plain funny. But Oregairu 2 is just plain high school drama. Nothing to supplement it. Just teenagers LARPing as adults. I can tell you right now, as realistic as the show was trying to be, no modern high schooler has the social or communication skills to act like an Oregairu character. It feels like a live action drama, not an anime. What I hate is how the show tried to hang on to the idea that Hachiman is some loser loner so poeple watching could still "ReLate" to him, yet he somehow has leagues of friends and people who rely on him and is able to convey his emotions through speech effortlessly. No loser can do that, but if we said the MC was a chad nobody could relate to him!!!11 There are also no rom-com elements. There's maybe a few hamfisted 'romance' scenes to egg on the viewers but we all get blue-balled as nothing ever comes out of them. Not to mention that no sane person would put up with the sheer animosity the characters have for each other. The show tries so hard to be realistic that it ends up feeling faker than it's goofy over the top first season.
In an attempt to part ways with the 'shallowness' of season 1, Zoku ends up becoming some pseudo-deep petty drama that anime-loving, "hachiman-is-so-relatable", pretentious high schoolers can write their grade 11 English class analytical thesis to feel superior to their small brain classmates who could never understand the deepness of why hachiman cried a lot.
As for art, sound, etc, it was completely adequate. Nothing memorable.
Overall, if you can tolerate the slow pacing, banal characters and story, then... there you go. A sequel to Yahari Ore no Seishun Love Comedy wa Machigatteiru.