The flashback scenes are cringe to the point where it really starts to distract from the show. They took the time to make the clothing look like 90s, and they were somewhat successful, aside from the fact that Beastie Boys never had a hoodie that look like that, And Wu-Tang didn't start selling hats like that yet.
The real problem is back in the 90s nobody said things were "epic" and definitely no one said " that's the hill you want to die on". I get it that they want to make this appealing to the young kids, but they've already used those slang terms in the modern day scenes. Why not use actual slang terms from the 90s, which would not only give the period a better feel, but maybe create a revival of retro slang. No one in the 90s said something was epic, they might say it was phat, or dope, or about 1 million other things.
In fact, there's a lot of things in this show that feel like they're just trying too hard to make it appealing to the younger generation. Most of the soundtrack sounds out of place, and I don't mean that it's an anachronism like the slang terms, I mean that it just does not fit the scene. They threw in certain songs just to seem cool, or to appeal to a crowd. But these songs have nothing to do with the mood.