In the Netherlands we got upgraded last year, just nfc your debit or credit card (or your phone if you use Google / Apple Pay etc). Not a great example of strategic autonomy, nor is it privacy friendly, but it really is easier then ever before. Super tourist-friendly, aside that you basically don't know how much you'll spend until you've already spent it. Next up they'll make it work with discounts and subscriptions, as right now you are always charged the full ticket price.