The EV supply chain in the US back in say 2007 certainly had far fewer key parts sourced from China than recent years.
As far as US EVs being subsidized early, if you take state and federal tax incentives, DoE grants and loan guarantees as subsidizes then that's true.
It's debatable (I think incentives applied to all suppliers not just US ones) but a reasonable statement.
Tesla given $60M by Obama admin when they were deep in debt and may have gone out of business.
so Tesla technically is subsidized by US govt. SpaceX too. Without NASA funding, they'd be long out of business.
China and US ain't that different.
China realizes that being a tech and industrial powerhouse working on future tech is great for their economy. They bet huge on it. That's how they win.
Europe on the other hand is now a laggard.