When I visit Thailand (no visa), I just use my Revolut card. I keep it topped up via my funds outside of Thailand, exchange “as and when” and draw from an ATM. I have the added bonus of topping up via Apple Pay which is linked to my credit card which in turn provides a lot of air miles! And there are no bank charges for international transactions… Not sure this would work for those retirees there (I might find out one day!) but it avoids a lot of hassle for me at least.