I'll start with what the show does obviously and unequivocally extremely well: the staging & cinematography, the acting, the set design, the sound design. Other people who write about television for a living can do a better job extolling all of the virtues Severance has in those departments, and they are all absolutely right.
(The one bit I'll add — I am obviously a huge Adam Scott fan. One of the biggest. I did not think he had the subtle chops it required to play two versions of yourself in the way that he does here.)
The show, as of writing, is in the nexus of "critical darling" and "all of my friends are obsessed with the show." I get it: it hits the sweet spot of prestige, good actors, weird, Reddit-pilled, corporate dystopia, Ben Stiller. And Haley and I loved it — we binged through it over the course of two weeks, our excitement level starting high and only growing higher over the nine episode run.
What I am worried about — and what I'm hoping they do well in season two — is that the show is really focused on giving answers and making it a thriller. It started out really working the message (what does this say about us?), and I think that was perhaps slower from a pace and payoff angle but is a much more interesting and rewarding show than the show it became in the last three episodes, which was more about the plot (what's going on to these people?) Maybe that's what you have to do, but I hope there's an endgame in mind that doesn't involve explaining each and every little detail and mystery, robbing the weirdness of all its potency.
(One of the things that Legion ↗ did really well here I think was give you enough background shenanigans to very obviously paint a picture of something is not right here, we are unmoored from reality without agonizing over having explanations for every single aberration.)
And, for the record, Haley and I predicted one of the two big plot twists. That's the ideal ratio, I think: predicting two means the show's obvious, and predicting zero means the show's illegible.