Usually the opposite of privatisation is not that something magically appears for free, but that it is funded by a state.

There is an SWE on the other side of this API - and I imagine they are enjoying a government salary and pension for operating it... people accessing it for free wouldn't impact them.

This carries the same energy as arguing against "free" healthcare by claiming that doctors shouldn't be expected to work for free.

Nobody is expecting anybody to work for free. We expect government to pay for it. I think you know this and pretend not to for some reason.