El Salvador made bitcoin a legal tender, Singapore has not made bitcoin a legal tender, the second country that makes bitcoin a legal tender is Central African Republic.
There are many crypto friendly countries that do not make bitcoin a legal tender, but still accepting it as a means of payment and for investment.
maybe for now Singapore has not been able to legalize bitcoin as a legal means of payment such as fiat money because there is still a fear of the risks that occur.
but it is also very likely that over time Singapore will legalize bitcoin because of the large amount of support from crypto holders or fans in the country and the existence of other countries that have started using bitcoin as a legal tender and after all bitcoin can help overcome economic and financial inflation in a country.