Bitcoin being a legal tender in a country is a different story compared to other regulations from some countries, Singapore is the best example by OP.
By design, with a decentralized network and non custodial wallets, Bitcoin does not require to be accepted as legally or legal tender to be used. All human can use Bitcoin. Legal tender is only a booster for Bitcoin adoption but without legal tender, it will still be accepted.
El Salvador's current situation on Bitcoin is superb compared to other countries even as you say crypto-friendly country. So, if Singapore will start using Bitcoin as an "official" legal tender, that's the time I can consider Singapore followed El Salvador.
El Salvador is a country with massive support from their president and government but after 2 years, we can verify that the adoption can not be reached by legal tender. Education first and legal tender can has good effect.