The EU market is super fragmented due to differences in language, culture, income and regulations so it would be nearly impossible to successfully scale a service made for Swedish consumers to the Italians for example. As another example, the Norwegians only pay with card while the Austrians only pay in cash.
That's why almost every EU country/region has it's own local website for jobs, classifieds, real estate, etc. All this fragmentation coupled with the lack of risk friendly VC funding means there's no chance for big players the size of FAANG to rise up from Europe.
When ambitions software companies from Europe have a good idea and want to grow fast, they just launch directly in the US market, ignoring the EU for the beginning. It's simply a much easier and profitable market.
Aral Balkan made a compelling argument at the EU parliament:
"You are acting as an unpaid Research and Development department for silicon valley. Because if a startup here succeeds, it gets bought by Google or Facebook. If it fails, we pick up the bill."
https://video.lqdn.fr/videos/watch/861c07f7-7e9b-4e64-9765-c...
Another variant I've observed is launching in the EU first, hiring locally at low cost but also having low profits. Then once the idea is validated, the move to US (sometimes literally moving the company headquarters) seems obvious.
Booking.com did it very well, but of course the audience for that is intrinsically mobile and cross-border.
I'll answer from the perspective of another European country(Germany):
Because all companies artificially cap salaries through a silent "gentlemen's agreement" where execs refuse to believe that a working class simpleton such a software engineer can be worth more than X amount of money no matter how badly they need to hire one.
There is not much in therms of competition when they all do this.
Sure, there's tons of opportunities if you're looking for a job, but when they all cap their salaries, the so called competition for talent means nothing in the end.