Almost all of those checks tend to happen after the fact and lead to transactions getting rolled back, rather than being checked in advance.
(Whether that's a desirable approach is a reasonable question, but that's already a thing that happens today. The only thing that needs checking in advance is "is there enough money".)
If Bitcoin can do it in 10 minutes globally, we can do it faster in a centralized system.
Edit: ... Not to mention many other developed nations' banking systems.
Edit: Not sure about the downvotes, but really- please don't pretend sending money instantly within one country is rocket science. The reason we're in this mess is mostly banks wanting to hang onto float, and legacy. Both our neighbors to the north and south have much speedier internal banking systems than we do, as do countless other countries.
How do you query the card balance and transfer the funds? Do you actually get cash out of the card, or do you have to resell it as a store credit to someone else?
(Whether that's a desirable approach is a reasonable question, but that's already a thing that happens today. The only thing that needs checking in advance is "is there enough money".)