While I had the same experience as you in high school (and primary school language learning was altogether a farce), I found the experience very different in classes at university. I think the primary factor was that there were a negligible number of unmotivated students.
Listening to other people at my level didn't seem a particular detriment because teachers have to speak at roughly my level anyway. They made more mistakes, but the instructors corrected them, and the corrections were valuable since they were often the sorts of mistake I'd make myself. Textbooks are trite, but since their main competition in the internet age is materials put together by dedicated but ultimately pedagogically-unskilled amateurs, I think they're better than most alternative prepackaged materials.
What I will acknowledge is that private study through a flashcard deck is probably the best way to acquire vocab, but that was never my biggest challenge. My vocab has consistently been on the large end of other people I've learned with, just because memorisation suits my personality (and I suspect that's true of a lot of people here). That never, though, translated to being the best in class - ability to fluidly construct a sentence beats out perfect word choice every time. It's also very easy to pair with a taught class, since there's no downside to learning extra vocab on the side.
Classes move a bit slowly, but I think the rationale is valid: You're here for three years anyway, you're probably trying to get to around B2, so we'll train you up to B2 in three years.
I'm not going to argue that it's as good as a private tutor, but it was closer to second-best than worst in my experience.