Jobs for devs are everywhere that's not what makes a city "startup hub imho.
The only "real" startup hubs are the ones where venture capital is available and these would traditionally be the cities in North America, China, Singapore etc.
Singapore is no way a startup hub. The only major thing going for singapore is its EDB influenced tax sops and seed funding matching programs like 1:4 or 2:5. In addition they have made it hard to hire foreign talents, local talent pool is super small, payscales are very low and worst of all their VC and angel have hardly any tech exposures. The PE scene is better
The only "real" startup hubs are the ones where venture capital is available and these would traditionally be the cities in North America, China, Singapore etc.