I feel like S4 fell into the same trap that Andromeda (and for that matter, the Star Wars EU) did years ago; "the Federation/Commonwealth/Jedi Order is gone --Until our Heroes bring it back completely in a single weekend, complete with an older generation who've apparently been doing this job for years."
It's ironic, because Star Trek has been trying desperately to be Star Wars for years, and the 32nd-century time jump gave them the perfect opportunity to have the 32nd-century galaxy just be the Star Wars galaxy; a mostly lawless frontier, full of smugglers, mercenaries, and bounty hunters tooling around in run-down light freighters that look like junk but are nonetheless a thousand generations more advanced than Discovery (sure, the Burn wiped out warp drive, but by then most people had switched to transwarp corridors or quantum slipstream, and human-level AI is so common that droids can be bought and sold second-hand).
Rather than easily rejoining the shrunken-yet-still-functional Federation, Discovery could have found a patchwork of successor states, forcing them to actually build a new Federation (or, more likely, something that only resembles their Federation while still being something new), complete with questions about how exactly to go about that --do they establish a government and try to legitimize their authority (like the New Republic did in SW), or start from the bottom, building a grass-roots coalition (like Enterprise did)? It would've given them a chance to address all sorts of juicy dramatic questions, like what are the most basic, fundamental tenets of the Federation, the things we absolutely cannot compromise on (and what are the things that that don't matter, or that we could genuinely stand to do better)? Why would local populations who were getting along perfectly fine be willing to sign on to this? What benefits does the Federation actually offer its members? What happens when you need the support of someone you can't countenance (say, who has built a prosperous nation on slavery or colonialism)?
" thing at the end of episode 1.