Flourish is a generous term.. There are countless examples of companies in all industries who will take full advantage of no regulations in the pursuit of profits solely.
And only when it's too late and they have caused so much chaos for people will they lobby for their own "symbolic" regulations.
There is a happy medium in there somewhere, but the US model is not it.
Mojang and Skype come to mind. As well as three of my former companies that are now owned by Oracle.
The EU market is definitely harder, it is not as contiguous and large as the US one, even the smallest required task: localisation, is hugely expensive.
So you can hit a critical scale faster in the US, sure, but any time anyone actually conquers Europe all that awaits them is acquisition.
Also, anecdotally, SMS was invented in europe so no need to regulate something already open and european.