It operates as a monopoly and 10,000 hotels have sued it for anti-trust in Europe.

Despite qualifying for DSA thresholds, the EU pretends it doesn't exist and is not a monopoly. Because it's not American.

Booking.com literally is classified as a VLOP (very large online platform) under DSA: https://digital-strategy.ec.europa.eu/en/policies/list-desig...

It's also not the only European company to be designated as VLOP, as you'll find some EU-based adult content sites on that page as well, but if you really want a European company that is inexplicably missing from this list, I'd go with Spotify.