From a real-estate point of view a condo and a co-op are very different things. In the former you own your unit; in the latter you are a shareholder in a corporation that owns the entire co-op building.

Thus only the former gives you an "ownership" directly akin to the classic ownership of separate plot of land, with established rules that have developed as to precisely what rights that "ownership" means.

[P.S. And an attorney will have much more work, and a much higher fee, for converting a building to co-op rather than to condo.]