Yep, you're being deliberately obtuse.
No, you don't understand how banking works. Even if they used government money to pay the interest, that doesn't pay THEIR expenses. It takes money to pay the cashiers, it takes money to buy bigger vaults, it takes money to hire guards, it takes money to hire accountants to keep track of all that money.
All these expenses could be cut by not allowing deposits. You don't need as many cashiers if you don't have depositors, you don't need to buy more or bigger vaults, you don't need as many guards if you don't have as much cash and you don't have to pay accountants to keep track of non-existent money. Without the ability to lend out the money it is a liability, not an asset. All you have is the storage expense for no benefit. All the money you are loaning out is now coming from payments of past loans and possibly loans from the Fed.
Under that banking system, the smartest thing to do is cut the branches by at least half and just loan people money. You might allow deposits from big corporations so that they borrow their money from you but that is about it.