I mean even after dominion war Cardassians have a lot of space and enough of warships left while Bajorans are force with few colonies and few ships mainly shuttle fighters.
Actually, Bajorans had an unholy number of colonies as the direct result of the occupation - there seemed to be a refugee camp style colony just about everywhere in Alpha, and ultimately in Gamma as well! Cardassians don't seem to have hindered the diaspora in any way...
What happened to these
worlds is an interesting question as well. Were the refugee camps abandoned in disgust after "Emissary" as the Bajorans finally could return to their homeworld? Or did the emigrants despise those who had stayed behind, and thus stay put for sheer spite? The Dominion razed the Gamma colonies; did Bajor demand that they be reinstated, and did it get what it demanded? Was colonization a brief folly that Bajor abandoned once all this interstellar nonsense was over with?
As far as we can tell, Bajor never was expansionist in its apparent hundred millennia of history - whereas Cardassia seemed to be exactly that for a long time, considering the balance-of-power arrangement involving the expansionist military was quoted as being almost a millennium old in "Defiant". Could Bajor overcome the inertia of those untold millennia and turn towards the stars - or would it resist the temptation instead, and shun anybody who left the homeworld?