The EU has an extremely fragmented digital internal market, laws that suck for startups in most places, worse capital markets and funding mechanisms (and related laws), and doesn't have a Silicon Valley. It also underinvests in R&D and doesn't have a DARPA.
So yes, just tariffing or restricting US tech wouldn't help much. Europe "lost" that race fair and square. It needs to focus on fixing all those things.
On the other hand a lot of these startups and tech companies are a net negative for the world. Externalise problems and pollution, internalise profits. We don't want society to be only decided by those who make the most money. That's why we have those laws.
I personally don't want the EU to become the US. And Investors gambling with other people's money is what gave us the world financial crisis of 2007. No lessons were learned as usual.
So yes, just tariffing or restricting US tech wouldn't help much. Europe "lost" that race fair and square. It needs to focus on fixing all those things.