I have mixed feelings about Disco ending. I really dug the first season's look at a Federation at war, and following the person who arguably set that war in motion dealing with her culpability. Add to that a ship that is part weird science lab, part haunted house. And yeah, I could live with the Klingon redesign.
It was inventive, it took risks and broke some moulds — and not always successfully, mind you. But I stuck with it from the hopeful "First three seasons are for growing pains" Trek paradigm.
Then the show took some odd turns. Rather than focusing on the crew's adventures in space and science, season two constructed a cosmic conundrum around Burnham and her family. I was still on board for the characters, even bearded Spock no matter how shoehorned in he felt. The show's unapologetic optimism was still a big selling point, too.
With season three came the time jump into a future that absolutely does not feel like it's a thousand years ahead of the previous season. The jump in technology should be proportional to a Viking longboat rocking up to the ISS, but it felt like a step back. And at this point, the extended crew of the Discovery was thoroughly sidelined: Burnham's personal relationships took priority over everything else.
For one example: As great as Michelle Yeoh is, the show basically redeemed a murderous space despot because... she reminded Burnham of her Starfleet counterpart?! I'm going to stop you right there, Captain "This is Starfleet" — this is a person who kept rubbing in Saru's face how familiar she was with the taste of his species' flesh.
I'll keep watching Disco through to its end because I'm invested in the remaining characters, but this isn't the show I apprehensively fell in love with anymore. Its strengths are all but gone, its faults enhanced, and its commercial(?) failure seems to have convinced the Powers That Be that future Star Trek needs to be grounded in nostalgia for previous eras.
I will miss the first season's promise of new, daring Trek shows writ large, and as much as I liked Pike and his crew in season two, SNW leans too heavily and knowingly on the franchise's campier canon for my taste (I know I'm in a minority with that opinion, and I'm not here to argue for or against). With peak TV fading, I'm afraid we won't see anything as bold as TNG, DS9 — or early Discovery — again.
That is pretty much exactly my feelings about the show, only I felt the high stakes in season 1 were warranted given we were seeing the Federation at war, which in itself is a nightmare for an essentially peacekeeping operation. Bringing in the Terran empire as a reflection on Starfleet's warlike posture in that situation was inspired, I think.
I have to say again, this being the first new Trek on TV since Enterprise, I gave that season a lot of leeway in terms of story and stakes.
As for character development, you're right — we did get to see small character arcs for Tilly, Saru, and Detmer. They were kind of drip-fed to us though, unlike the more ham-fisted Burnham bits like season 2's "let's telegraph her broken relationship with Spock by having her dead mother plant signals across the galaxy". There were a lot of nice character bits in there, but it was mostly plot acrobatics to centre everything on Burnham, again.
I loved Tilly and her friendship with Michael, but I'm split over the journey Tilly did get. One of the first things she said was "I'm going to be captain one day," but as it became clear that Michael was headed for that seat, Tilly got an abrupt arc of self discovery that made her decide to be a teacher instead.
Is it cool to realise that your goals are maybe fulfillments of somebody else's dreams, and finding your own way? Yes, I love it! Did it smell a bit like the writer's room backpedaling to make Michael even more awesome? Yes. Yes it did.