Singapore has NETS payment network, https://www.nets.com.sg/
Small shops use NETS only or cash. Visa, MasterCard, Amex…nothing works. One should either pay cash or NETS card, that’s it.
That’s why one must carry cash and a reserve forex card loaded in case one needs cash.
Credit card and debit card (Niyo Global) with zero foreign currency mark up fee can save you much.