There seems to be some misconceptions here. This wasn’t arbitrary. Most acquisitions are not blocked. The US government can block a lot of things for companies,

There seems to be some misconceptions here. This wasn’t arbitrary. Most acquisitions are not blocked. The US government can block a lot of things for companies, but is generally speaking pro-business. That said there’s a longish history of regulating monopolies, in order to benefit consumers and the economy, so no evidence of a new trend wrt Europe based on this case. (Consider whether that history may be part of why the US had a lead in tech entrepreneurship in the first place.)