Different countries within the EU have different laws, different markets, different cultures, different ways of doing business, and most obviously, different languages. Germany is different to France is different to the UK is different to the Czech Republic is different to Turkey.
This is why there's no single "European search engine" - and this is why America is the most attractive (and competed in) market for digital products - it's huge, well-off, and it's a lot more homogenous (at least in language and general culture) than Europe.