Using a centralized exchange in another country and the tax consequences? (Reddit Bitcoin)

What could be the tax consequences if Coinbase left the US and headquartered in the UK? If you live in the US and used Coinbase UK as a centralized exchange to buy and sell Bitcoin what would happen if you incurred a capital gain?

You would owe the capital gain on your US tax return of course but would there be any tax obligation in the UK, even though you don’t live in the UK?

I’m not that comfortable with the idea of using a dex. I’m just wondering what the options would be if the US environment becomes restrictive enough for Coinbase to move to the UK, what the options would be.