Subscriptions are often done via "direct debit" ( since 1970 ), which is safer than letting anyone take money if they have your details, so that's been a solved problem here for a while too.
The downside is the first-movers problem, where the UK having been ahead a couple of decades ago will now likely be behind for a while, because there isn't so much incentive.
Hopefully not as long as the USA has been behind though!
How so? I just tap my mobile on the terminal just like tapping my debit or credit card. In Norway that works with both Google pay and Vipps.
The advantage with Vipps is that I can also pay other private individuals knowing only their mobile number and the payment is instant.
The only way I would use such a system for purchases would be if the merchant refused debit/credit cards, and even then only if there wasn't an alternative merchant I could use.