After watching the first episode of Season 3 of Star Trek Discovery, all I can take this show is as a non-canon parody that takes itself seriously. The whole thing about all the dilithium in the universe going boom at the same moment is badly written comedy and makes no sense.

Even as a soft-fan of ST, I can say that dilithium was less a power source and was used to regulate the flow of anti-matter. It itself was not used to power warp and it going boom doesn't destroy stuff. ST has had exploded crystals before with zero damage.

Even if we allowed the total destruction of all dilithium in the universe, alternative modes of "powering" Warp drive exist in-universe. Romulans had their singularities, God knows what the Borg used. The bottom line being, many species used different methods to achieve Warp.