They manage to do it for 50 states in the US just fine. It isn’t exactly rocket science. It’s just that individual countries in Europe all feel like unique little snowflakes.
nobody in an EU member state thinks of themselves as a "state" in the EU, they're a country but in the EU
nobody would want the US kind of federalism. not to mention there isn't a single majority language aside from English for those that know it well enough
It'd be interesting to see the US try a real federation, but recent evidence suggests that's beyond its capabilities.
The US / Trump doesn’t even manage to renegotiate a trade agreement with Canada, although you speak the same language and your cultural proximity is about 95% - so maybe it’s time to get off your high horse buddy