Co-OP and condo are similar but different. In a co-op you own 0.x% of the building and are granted exclusive use of your unit. In a condo you own your unit and I think 0.x percent of common areas. Converting a co-op building to a condo causes a huge price bump as mortgages are easier to get for buyers coming in and people understand condos better.In a co-op condo? My parents were supers in one. Free rent and a salary.
Hell I considered it a few years back but wife said no. Not sure what supers are paid or how they’re compensated now a days. They’re more property managers that sign off on work than anything.
As for your parents, co-op probably sold n-1 units. Build 100, sell 99, every buyer owns 1.01%. That leaves a suite for the super owned by the collective.