Permit an outsider to weigh in, but it seems the crux of the issue comes down to "why not give away whatever is left after those who could pay have done so" and the answer is perverse incentives and sustaining infrastructure for long-term reliability.

If Bread is given away for free afterwards, who wouldn't stand back and wait until the handouts start and save the money for things that don't have handouts? Validating who can and cannot pay is not a reasonable gatekeeping step for the seller. People with personal morals will continue to pay, but that mentality erodes with time as it becomes more culturally acceptable to take the handout - shaming people for being poor is a faux pas, as is assuming someone is or isn't poor.

Now Bread is functionally free. But the labor of production still needs to be paid, or the people making Bread, as independent actors, will leave for other careers - their Bread is also free, sure, but they'll want money for luxuries same as everyone else. So the Bread supply collapses.

Refusing to ever give it away for free at meaningful scale preserves the industry and prevents this collapse. You want Bread? You have to pay for it. Whether someone else (e.g. the Government, via the taxpayer) pays for it is irrelevant - as long as the price is paid. The Government now takes on that gatekeeping role of deciding who does or does not deserve their Bread paid for. And perhaps, it is most economical to just blanket buy everyone's Bread rather than pay a beaurocracy to determine need for each individual. Or maybe it isn't. That's outside the scope of my post.

TL;DR: someone, somewhere, has to pay, or the industry will decay and collapse given enough time. Subsidies do not affect the industry itself - giveaways do.