Basically, as the question asks, and by adoption, I meant adoption at merchant level or peer to peer level.

In the case of US, there are already state governments like Ohio that accept government payment and services paid for in Bitcoin, along with a decent number of merchants. There are real estate sales being settled all over the country (and more often in Florida) being settled in Bitcoin too.

Switzerland, in particular, is also a pioneer in Europe, obviously, with cities like Lugano and Zug thriving with Bitcoin based startups and merchants accepting Bitcoin. It obviously lacks the scale of the US, but in those cities in particular, it is totally possible to live with Bitcoin without touching fiat (except accepting your salary in Fiat if you are at a corporate job).

I chose those two examples to show that the size and scale (or lack thereof) are not a constraint, as one is a gargantuan sized economy, another much smaller, covering both ends.

But the UK? It seems the prevalent notion is Bitcoin is a scam. Am I correct to suspect that it is because half of the GDP of London comes from the financial and banking sector, which got a chokehold on regulators to protect the entrenched financial institutions and their bureaucracy at any cost? Or is it down to the increasingly socialistic mindset of the Brits?