I don't think that the web "stole space;" whatever possibilities and promises space has still exist.

What did happen: The web and space both have trancendental allure; they offer, or seem to offer, an escape from the quotidian realities of life.

Space travel is hard; settling space would be even harder. And WAY expensive. It would require the dedication of enormous resources for a really long time to get the ball rolling, and even then only a tiny fraction of humanity would get a chance at the supposed trancendence via actual travel or settlement. (Then there's the strong possibility that living in space would be a boring drag most of the time. "No matter where you go, there you are.")

For the vast majority of humans, the trancendental allure of the web appears more immediate, more accessible, then that of space. Indeed, a sort of faux trancendence, via participation in absorbing games, is already at hand.