I feel like they didn't really want to think through all of the implications of what a Federation 800 years after TNG, DS9 and VOY would mean. It's almost as if they thought of what would look "cool," like programmable matter that can shape shift, sleek white sets that look futuristic, and warp nacelles that float disconnected (personal aside ... those floating nacelles are still something that I think is one of the dumbest additions to canon), but didn't think out how the structure of Starfleet and the galaxy they inhabit would evolve over 8 centuries.That's one of the weird things about the 32nd century for me too. If anything the Federation and Starfleet in the 32nd century should be more like something out of the Culture novels than TOS (One of the things that DIS: "Whistlespeak" did really well, even though in general I didn't like that episode, was the "eyecorder" tech and how well the undercover-in-a-primitive-society thing worked). We're seeing literally centuries of stagnation where the only major technological development seems to be Tron lighting!
And yes, the Burn, yes, suddenly dilithium became an incredibly important mcguffin again after TNG/DS9/VOY and even ENT pretty much ignored its existence beyond a mention or two... but even so. Why by the 32nd century can't you just replicate dilithium? Or use holographic dilithium? Or not have dilithium at all because why do warp drives still apparently work the same way after nine hundred years!? I don't really want to watch Star Trek for its take on a technologically regressed post-apocalyptic world.
For example, why are they still limited to warp drive?
We know from Voyager the Borg are using transwarp drive in the 24th century. We know the Borg figured out a way to even create a transwarp network through the Milky Way. And that's even before you consider that Voyager had fooled around with quantum slipstream tech that's implied to be even better than transwarp. In all of those centuries, the Federation couldn't replicate that tech?
The only reason I can think of that they didn't want to introduce those concepts as being the new normal is that they thought it complicates the "specialness" of the spore drive.