This is exactly how it currently works.
But what I meant is that it is not easy to convince generic business to accept cryptocurrencies due to legal barries. This applies to Monero much more than to Bitcoin, and for some non-techy business it is easier to adopt Bitcoin by using custodial service, which is not available for Monero (at least in Europe).
Monero is cash and can be treated as such. With Bitcoin a business is required to KYC and if any part of a transaction has what the authorities consider to be taint then your entire transaction can be frozen and the coins confiscated from you and the service not rendered. No thank you. That sounds like a horrible way to conduct business. Besides, custodial equals IOU and IOU equals can be removed at any time for any reason.
Your arguments are good, however if they did work no one would use banks. Unfortunately, all businesses I know have at least 1 banking account.
That's because until now there's never been a choice other than holding a ton of cash at your business, physical location, which is inconvenient and quite frankly dangerous.