A huge amount fell. God told them to eat their fill, but don't save it. The hungry wanderers ate to their contentment, and some of them stored the left over manna in jars. That leftover manna was rotten and spoiled the next day, but God sent them more.
God could've dropped magical non-expiring bread. Instead he dropped preservative-free no-shelf-life bread, and told them to trust that he would provide for them.
I've always interpreted the "daily bread" as being a reference to the manna. It seemed like it was acknowledging that they need to trust God day-to-day. It's not a one time "Here is the solution to all future concerns", its a daily trust.
So I think the debate is, if one wants to have it, is the prayer saying "give us our bare minimum to survive" or "give us our plenty that comes with an implicit trust that the plenty will continue"
But its a weird concern to have IMO. Especially since Jesus likely never spoke the word epiousios at all, he probably said something in Aramaic or Hebrew or something. I'm also in the "This wasn't a literal 'say these words' guide, it was an example." Both instructions seem in line with the rest of what Jesus was teaching; be thankful and trust God.