But season 4 has SO MUCH going on that it's so much more rewarding to keep returning to than any other season of the show. It's one of the most original seasons of TV ever made. It takes full advantage of the all-at-once streaming model in a way that still hasn't been topped (or even remotely approached). It's a mess for sure, and there are plenty of glaring flaws, but it's so damn audacious that I can't help but admire it more and more even if the jokes don't land as frequently as they do in the first 3 seasons. It felt like they were pushing TV in a direction that nobody was remotely ready for and I loved that about it. Like if they couldn't be as reliably funny as they used to be, at least they could still forge new directions and reinvent the entire medium in the process. (and the remix version, while being mostly inferior to the original cut, makes the season even more layered and dense since it gives you a different window to see the events of the series through, plus it even throws in some extra details and alternate jokes here and there which is a nice bonus)
After all that season 5 feels like a regression. They could have continued in the ambitious and experiential direction of 4 but fixed the things people had problems with (not having all the cast at once, the pacing being a bit too slow, bad green screen, over-reliance on narration, ect), but instead they just went back to the old style and it just kind of feels like they're going through the motions a bit. Like they backpedalled so hard after the season 4 backlash that the series has nothing new to offer anymore. it does feel like the old series in pacing again, and there are plenty of great laughs. but like season 4 it's still not on the level of the first 3 seasons, and also like season 4 they still don't have the whole cast together a lot of the time (most egregiously, Lindsey all but disappears for half of the season), still use green screen to cover the gaps (which is still awkward and distracting), still use too much narration and recap, and still dont land jokes with the frequency of the original seasons. But unlike season 4 there isn't really anything new here. It's just a bunch of average arrested development episodes, which is a fine thing for sure. but s4 being as weird as it was gave the show a reason to keep existing a decade+ after it originally began airing, s5 doesn't really do that.
It's definitely still good (I probably liked it about as much as you did) and I hope the series can continue for as long as Mitch Hurwitz is still passionate about making it (and if he's not passionate about making it anymore, that it gets a decent ending and we aren't just left hanging). But I do find it pretty telling how online discussion of season 5 pretty much completely stalled maybe a week or two (at most) after it came out and if you bring it up people say they liked it but dont have too much more to add. Yet season 4 still ignites discussion and heated arguments. There are still 8 more episodes of S5 to be released though so we'll see where things go once those come out and people can start to rewatch s5 in full.