More to the point, DSC establishes that the Federation still exists as far ahead as the 32nd century. If anything, from a historical perspective, that's amazingly optimistic; cultures don't tend to last a thousand years without collapsing and being replaced. It speaks to the Federation's resilience in being able to survive cataclysms and the periodic generational swings between fascism and inclusive democracy that all long-lasting cultures encounter.
Yeah, when you really put it in context like that, we just happen to see the Federation and Starfleet in what's likely their darkest time in the next millennium, which is good for Discovery because there's a problem to help solve, and a little easier to write than a Federation at its apex would be.
And since we know divergent timelines can happen, it is exactly as possible that a given show we're watching is the divergence point for a new bad future as it was ever possible that this week the anomaly was going to eat the ship and everyone would die, which is to say, we know it won't happen, but both the everyday and the galaxy-spanning threats in the present aren't really undercut by having a future play out that happens to be the one we periodically visit or have crossovers with or whatever. Most franchises would really suffer a little from having a the-future that was 1000 years out ahead of the present, but Star Trek seems to pretty much get away with it without losing anything.
So there's no cost, I'm just not convinced of the benefit. It gave Disco as a show somewhere to be displaced to, and that was good for Disco. The geometric ships with shiny-sleek hulls and detached bits really are pretty much the exact way I'd want to imagine incomprehensible deep-future Trek technology, and all the wildly convenient personal teleportation and commbadge tricorders are really pretty inevitable progress and sometimes cool. Star Trek has to maintain a balance between, on the one hand, relatably human characters doing stageably interesting things on screen, and on the other, the implications of what the technology could really do, and the Disco future just shaves a thin little slice off that block of normal relatably human spatially embodied action. (And programmable matter has been a bit underexplored and underutilized for ship functions IMO, while using it for adaptive interfaces instead of the ubiquitous, cheap solid object holography of the late 24th and early 25th C. actually seems to rein in some of that potential detached virtualness.)
It was all
very good choices for Disco.
But space is still the same space and most of the species around are the ones we know, so it hasn't really opened anything up on that front. There aren't any other ships or locations we've got to know and care about. There's nothing to really attach to. I hate to say it, since I'm not watching it, but Prodigy seems to have done a lot more of that literal and figurative groundwork in making a new space in the Trek universe I'd want to go play in ... and it's within this couple of decades constituting the Trek franchise "present".