I started reading the books and it seems like a lot of subtleties got thrown out - there's an awful lot of "Drama" injected into the series by having the characters make stupid decisions/hiding irrelevant information just so that it can be 'discovered' or reversed later,
I also get the feeling that they stopped bothering to remember the setting was mostly supposed to be "Hard" Scifi, outside of specific references to the books, but that's a pretty specific complaint.
I didn't love the books because too many of the sentences are weak, obvious, or clichés: https://jakeseliger.com/2016/04/28/briefly-noted-leviathan-w... , but I gave the show a shot and hoped for something better than what it is, or what the first few episodes showed. Still, I think the cash shortfall problem is probably real and accounts for some of the show's challenges.
I'm reminded of SyFy's making of The Magicians, which is a lovely book (https://jakeseliger.com/2009/08/28/the-magicians-lev-grossma...) and a TV show that I really wish HBO had made.
The show is made for middle/upperclass teenage white girls, is the book for a different audience?
At least here in Sweden it says "A Netflix Original Serier" at the start of each episode, so I'd assume Netflix is at least partially funding it already. In fact is was only very recently that I discovered that it wasn't a Netflix exclusive show in the US.
It stings to see characters go underdeveloped for any reason, whether it's poor writing or simply mismanaged priorities like you mentioned.
I'm happy that the show has survived the weakest part of the book series - Detective Miller - and gotten past the admitted cribbing from Firefly without looking derivative. The show has truly gotten stronger from every episode.
One change I would make is to subtitle the Belter dialogue. It's such a fun part of the books which in translation to an audio track ends up getting lost as a word-mash.
HOWEVER! As far as whether the show will survive: The show either needs more cash, or to allocate that cash in a more narrow, strategic, and modest way. It suffers the problem endemic to all under-budgeted TV sci-fi: the low budget always visibly bleeds in at the edges. "Yeah, that actor's really not the best fit for that part, and we could have made the plot easier to grasp with an additional scene, but with the money we save, we can afford some CGI for the rail gun!" Maybe it's just me, but I would rather watch an excellently executed sci-fi drama on an obviously artificial Dogville-like set than watch an "OK" space opera that has a nominally realistic looking space-ship brig which I won't remember anyway.
(Not to diss The Expanse's actors! - the majority are quite good, subtle, and growing on me with each episode.)
Action and special effects together are the number one self-defeating conceit of all sci-fi, especially television sci-fi. In order to please the action-craving audience (I guess?), they starve the heart and soul of the show: focusing on characters. What I love about Star Trek: TNG, one of my favorite shows of all time, is that in the Riker's Beard Era, it focused on the truth and depth of the characters through and through. That focus allows the audience to overlook the latent camp of the setting, and forgive the sometimes poor execution. As a result, TNG is still watchable today.
Special effects age. Characters are immortal.