I'm curious, what big EU tech companies so big they would be subjected to regulation? AFAIK it's mostly telcos, consulting and semiconductors makers. Telcos are already heavily regulated (at least here in Italy), the rest doesn't really quality for consumer protection laws being B2B.
I'm not really sure how EssilorLuxottica is relevant to questions of digital markets, but I do agree that the US should break them up (at least in the US market).