Indeed. In many quarterly reports of large tech companies, the revenue from the whole of Europe combined is sometimes bigger than that from the US. European revenue is often a close second.

It's truly significant if this revenue dissapears. Which is why I am baffled by how e.g. Zuckerberg is flailing at Europe and the EU. If EU regulations cut services off, or users move elsewhere out of fear or disagreement, that would be a crippling drop in revenue. For some tech companies enough to put them under, I'd say.