My theory of why Lower Decks works (at least for me) is because it's basically a slice of life show and that's what the majority of old Trek is. (It's just exaggerated for comedic effect.)
Old Trek felt like individual episodes with a particular moral or existential question, simultaneously broken up with 1 or 2 character development based plots, interspersed with special moments/major plot lines and disasters at specific points in the series that would hook you to the screen _(anyone else remember the first time we had a double episode or met the Borg and how incredible that felt?)_.
A lot of new Trek feels like an action series or a Marvel movie, which is fine, I like those and I like the new Trek shows enough, but it's not what I look for in Trek, so I get bored at some point and stop watching.
Lower Decks is the only one I find myself actually wanting to go back and watch more of because it feels like it's doing something that only Trek could do, instead of what any sci-fi could do that just happens to be in a Trek universe. No hate to anyone who likes it, and I don't think they are inherently bad shows, just not what i'm looking for.
In fact, it's the exact same reason why I loved all of Stargate but then gave up on SG: Universe pretty quickly. If Universe wasn't branded as Stargate I might have liked it, but it didn't feel like Stargate so I moved on. It set up an expectation for me that it didn't meet, so it killed the initial excitement and that never came back.
Don't get me wrong, I don't just want them to just copy TNG, it probably wouldn't succeed the same way today, and having diverse show formats/genre's is a good thing, but I wish they would explore creating something that only Trek can do and that makes it different from other sci-fi. There is some of that in new Trek for sure, but nothing feels quite unique to Trek yet outside of shows like Lower Decks.
_Sorry for the wall of words, i'm stuck on hold on the phone and got a bit carried away haha!_