It's not that different from how it was at launch.
It absolutely is. I don't know if it's still active, but at one point recently, they had an instance up where you could play from the original launch coding, just to see how much things had changed.
Probably feels like you're playing a game because you're, um, playing a game? They redid sector space recently and got rid of a ton of load screens, so you can now fly for what feels like forever without reloading. Not sure how you think you would get from sector space to a system (or mission) without a load screen, as it would just be a massively big thing that way, plus there are different mechanics involved in how the missions work. Imagine the bug where the bad guy you have to kill just wanders off and is off in the DQ when you were fighting him around Vulcan. Hell, try beaming down somewhere, even if you lived real life in the Trek universe, that's a NATURAL load screen. Never heard Kirk complain about breaking immersionThere are still way too many load-screens for instance. You can't just fly your ship straight into earth-space-dock. The load-screens popping up and reminding you that you are playing a game. It's like playing an old CD-based game it's so chock full of load-screens.

Again, are you basing this off of the Beta, or have you played in the last 5 years? This WAS a big problem in the beginning, but has been changed drastically since. Still a few patrol missions and whatnot, but way more Featured Episodes, remastered content, and variation in how you get there. The days of scanning 5 things after fighting 3 groups of bad guys near the asteroid that looked like a donut are mostly gone.And there is so much instancing and repetition it really doesn't feel like an MMO. It feels like a multi-player game with some hardcoded missions that repeat over and over again.
The ship models are also looking increasingly crude as they haven't gone back to increase the detail of any of them. And they aren't fully functional. You can't fly a shuttle in and out of the shuttlebays, for instance. The shuttles aren't even in their proper scale.
It's just plain outdated.
yes, they HAVE gone back specifically and redone a bunch of models. When was the last time you checked? The Galaxy class just got a total redo in the past 6 months or so, know there were a bunch of others. Voyager also got some nice stuff done. Whether you like the design of the new ships (admittedly not all awesome), the models are the exact opposite of the "increasingly crude" that you're stating.
Honestly, a lot of the stuff you're complaining about are NOT problems with the game, and some of it is just plain wrong. Problem seems to be that this MMO is not what you want it to be, and it wasn't designed to appeal directly to you.
Fun enough game, although has its issues, and is more grindy than I'd prefer. Wish it had more 25th Anniversary-type game content, but it is what it is. It's NOT that, plus a fighting game, plus Bridge Commander, plus Armada, and Quake, and an interactive Star Trek museum. It can't be. An impossible standard to hold it to.