It all depends on government regulations, as banks adhere to the regulations of the governments in which they operate. If the government allows them to accept Bitcoin deposits and withdrawals directly from their customers, then it's perfectly legal for banks to accept Bitcoin transactions directly from their customers.

So it's entirely possible for banks to become a medium of exchange for Bitcoin assets.

As for when that will happen, it all depends on the government, because most countries do not allow banks to fully engage with cryptocurrency because they consider cryptocurrency to be a speculative asset.

But we understand that banking is a business, and when a government allows banks to get involved in cryptocurrency, they will certainly maximize the opportunity to accept bitcoin or altcoins from their customers because it has the potential to provide them with a new source of revenue.