Ironically enough the country that actually embodies the concept of an Ummah as sad it is to say is… Israel.
United by them being Jewish. You can be American, Indian, European, Chinese, Iraqi whatever else, you can get citizenship purely because you are Jewish even if you have never set foot there in your life nor did your forefathers for centuries and centuries
There’s Americans willing to betray America because they’re Jewish and have loyalty to Israel.
Even pre 2023, if a Muslim in Asia wanted citizenship in Palestine, it wouldn’t have been straightforward, and who knows if they would even get it.
The concept of Ummah isn’t the issue. It’s the fact that Muslims esp those in power have abandoned it for at least a 100 years, but honestly longer than that. Muslims with weak faith think that overnight it can be implemented and if they don’t see living standards improve the next day then it’s all just theory, while those in power have sold out caring about their Muslims brothers and sisters to fill their coffers even if it means turning the other way from what’s happening with the Uyghurs, Sudanese, Filisitnis.