China has more people and is better organized (read: authoritarian, but competent). They can do any project they want without corralling cats. The EU needs to balance the varied local politics of their members (half of which are totally dysfunctional) and each democracy in the EU needs to balance electability with subservience to their sponsors. It's a pretty bad way to get anything done, even if the citizens wanted it, which in this case is a strong "maybe."

Because they just ban US tech and then the local companies don't have any choice beside building something themselves.

Because the EU "elites" are captured by the U.S. and pursue U.S. interests rather than EU ones. They work in U.S. companies, get bribes and positions from U.S. companies.

Also they speak the language of their competitor, which deludes some into thinking that U.S. interests are the same as EU ones.

During the Schröder/Chirac era it wasn't as bad. Only the UK was completely captured under Blair (perhaps the common language played a role there, too).