I Revolut has already opened office in Singapore and they have been hiring staff for Singaporean operations for some time.
N26 is only available in Eurozone countries and there are still several non-euro states in Eastern Europe, some of them with large populations.
True about Singaporeans without passports. Not travelling from Singapore is almost like living all your life in one city! I went to Singapore two months ago for the first time and loved open air food courts at night. I can’t remember their names but choice of food and atmosphere were something to die for.