With social networks or any EU startup problem is you have to deal with different languages right at the start.

Being US startup with English only you have access to 300m people right away.

There were country specific social networks but then all cool kids were on FB so everyone moved there.

The same with LinkedIn, our country specific business social network closed down finally last year. First 3-5 years it was growing then everyone moved to LinkedIn so that network was ghost town for 15 years someone kept it alive just in case but seems like they stopped wasting money.