I feel "You" ran out of steam, for me at least ,near the very end of its first season. To the point I can't make myself finish watching S1, not right now anyway.
It's difficult to say why exactly, but I will offer my own theory.
I bought in near instantly, I was totally immersed first 2-3 episodes. It was one of the most entertaining stretches of watching any TV series ever for me. Maybe it's because this isn't my typical viewing, but I found it so fresh and its pace moving astonishingly quick. It was a thrilling ride, a wild fantasy, but very bold and well written.
That amazing first impression is what had me doubt it can sustain itself the longer it went, I mentioned it earlier and it came true. In my opinion, "You" gives its viewer too much and too fast and spoils them as the result. It then tries to grow its story and even give you some trying twists and/or intrigue, but its too late - there's nothing the script can do anymore, it's too late! Yes, the writing is still good and I do like the actors, but it's stale and old now because you exploded out of the gate so damn strong.
I'd still rather have it this way than the opposite, even if the show it "ruined" for me now. Still, those first few hours were magical and worth it.
I will try and re-visit, my hope is they go scorched Earth in S2 - it has to be nuclear or this one is dead on arrival IMO.
P.S.
@Runner77 Would've been an epic mini-series.
P.P.S. No, in all seriousness - this would be a riot framed in 3 or 4 hours. An absolute masterpiece. Not grounded in any reality, that is its strength, not weakness. Let it come at its audience like a tidal wave wrecking all in its path and be over in an instant.