Take the buses: They have the most amazing automated machines for giving you change from banknotes and then collecting/calculating the correct fare payment in coins. Similar machines exist in some retailers. Try to pay by card and you won’t travel very far.
Much of the rest of the world moved to contactless card payments over a decade ago
I sort of sympathise on some levels - the investments they made in these ”refinements” are not trivial. I suspect Japan will stick to its legacy processes. IMHO It will succeed as a niche curiosity that outsiders find interesting as the world passes it by.
I have to wonder if such curiosity tourism will ever be enough to cover its economic needs.