Bajor's only about 60ly from Earth, a 24th century shuttle craft, most of which relied on fusion reactors for warp travel, could have made the trip in somewhere between 1-3 months.I appreciate the comment. But I disagree.
First, for most practical (i.e., actually implementable) purposes, up through DIS season 5, they did need dilithium. I vaguely remember a whole line of dialog from Vance (?) about how Starfleet has investigated a ton of alternative warp options but has failed at them all till now (frankly ridiculous, given the variety of technologies we have seen in Trek before including Romulan sigularities and spacial trajectors, etc., but that is Discovery writers and the power of plot for you). Second, given what Trek has shown us, fusion reactors, as powerful as they are, would never generate enough power for high-level warp, and additionally would require too much on-board fuel. And Bajor is a long way away, low-level warp wouldn't get you there in a reasonable time even for a half-lanthanite.
It's more likely that I am forgetting more instances of warp travel in the post-Burn era. Enough such that interstellar travel is feasible, just not enough to hold a large (100+ lightyear) political entity like the Federation together. Or the show just forgot that it should be extremly hard to get to Bajor.
Functionally speaking, and assuming Warp Travel was the only possible method of FTL, it would have basically been a return to the "Enterprise" era where you had "long haul" transports with months of travel time needed to get between various far flung Federation worlds.
Realistically though, even assuming no way was ever found to stabilize synthetic benemite, they would have just started constant synthesis of the crystals on various worlds and created a network of gas stations that allowed ships to replace theirs immediately any time they de-crystalized.
Or set up transwarp/subspace corridors between systems.

Speed of plot.