Hundred years with a paper cash? Are you serious? While they still accept it with groceries and smaller amounts, they won't even accept with larger amounts.
Large or small, it is still the first mode of payment in majority of shops out there. Digital payment systems with fiat have come up but bitcoin is nowhere to be seen.
AML laws will prevent all big paper cash purchases in the future, they are already being prevented in some stores. Even banks require a proof of trail for that money when you try to deposit it, and washing that money trough businesses that have accepted paper cash, has been a problem they are now going to deal with.
It might be so, but AML has been here for years now, and still people use paper cash and sometimes digital payments. This problem will exist and the governments are slow to control it.
Even without AML, it's just impractical for stores to hold large amounts of paper cash. It's a security risk, and security for banking that money costs additional money.
Digital payment modes are there, most of the younger generation have adopted it, but they have not started using bitcoin. So cash is still king.