American unions are quite different from European unions.
Even the UK does public transport better than the US, and our union/management relations are very similar to yours.
They mostly remain in public sector monopolies, where they in some ways are stronger than politicians and management.
I don't know of anywhere in Europe that's similar. It has little to do with "militancy" levels.
Our public transport system still works way better than in the US. And I say that as someone who actually likes Amtrak.