Are you seriously arguing that slavery wasn't profitable for plantation owners?

Aside from being dangerously close to "well actually we were doing the slaves a favor!", that argument is absolutely absurd.

Do you really think that they couldn't get more economic value out of enslaved labor than they put in in shitty food and housing? By that logic, the poor poor plantation owners could just barely scrape by on a subsistence income. Does that match up with the lavish estates that we see in the south to this day?

Aside from being illogical it's also ahistorical - milenia ago the Romans had massive slave-based plantations generating obscene wealth.

... what.

A plantation own has to provide all the things you mentioned to whatever form of labor they're using (free/paid or slave) either through wages or directly.

It's much cheaper to provide those things directly, and cheaper still when they're not in a position to complain about the quality of them.

A slave worked more hours, every single day, while eating the cheapest food available. A slave slept packed into a cheap, tiny, overcrowded shack. A slave couldn't demand time off, higher wages, or quit. A slave could bring in income when their children were sold.

Everything else aside plantation owners were businessmen. They used slaves because they were the cheapest labor available.

Reconsider whatever choices led you to this