This. Sure, Admiral Vance could just be a human conciousness in a floating spherical robot and Federation starships could just be torpedo shaped probes the size of a car that could fit hundreds of uploaded consciousnesses, but would any of that be interesting to watch? Absolutely not. The people complaining that Discovery isn't doing Trek right, would still complain that Discovery isn't doing Trek right. For starters, we saw how mad people got when a fleet of the same class of ship showed up in Picard. Now imagine, the fleet gets replaced by a bunch of torpedo casing-like probes and the Enterprise is now a sphere and the size of a motorbike. The ship nerds would be outraged just as they were outraged at the more weird 32nd century ship designs, which 'didn't respect design lineage'.
Trek has shown that technological stagnation is actually kind of normal in the trek universe. The Dominion have been around for 10,000 or 2,000 years depending on which Weyoun you ask and they aren't that much far ahead in terms of technological capability. Klingons have been spacefaring for around 1500 years, Vulcans and romulans for around 2,000 years, the Bajorans were a pre-warp culture for 20,000 years and said to have been building cities while man was still learning to walk upright, and none of them are floating heads in jars or have technology that monkey-brained humans couldn't figure out. There's no reason why the Federation should be some iain Banks culture-like entity thousand years into the future when it's firmly established, that no civilisation in trek evolves into that.
