That doesn't sound like a great design from a UX/speed perspective. Is it better than it sounds?

That isn't specific EU regulations. SEPA is both the way payments are cleared and EU rules so works cross boarder. It is the foundation (interbank infra) upon which PSD2 layers a requirement for what amounts to having APIs, and a requirement to make the API open-access, in the sense they can't privilege their own systems over these APIs. They solved (or at least it seems like they might) one of the bigger blockers of building fintech solutions: a level playing ground.

It's pretty easy to make a secure payment method for one-off payments or fixed-price regular payments. A lot of the value of credit cards is that you can use them to pay for things that do usage-based billing, without having to do anything after the initial setup.

That's what direct debits (Avtalegiro in Norwegian) are for. Works fine here. I only use my credit cards for buying things in shops or one off things online. And my credit card gets paid by direct debit.

Indeed, and in the Netherlands there is something similar to Avtalegiro as well, since more than 20 years ago. And depending on your bank, they even make it easy to reverse a charge up to three months after it has been made if you don't agree with it.

Direct debits have all of the dangers of credit cards and then some - you have to give out a numeric identifier, and unlike a credit card that number allows pulling directly from your bank account.

"Direct debit" can mean multiple different systems. In this case the Norwegian system the parent talked about sounds similar to the Finnish Finvoice system that can be used to (auto-)pay practically all bills in Finland - the system is known to users as "e-invoicing" (e-lasku) or, if used offline, as "direct payment" (suoramaksu).

The customer manually creates the billing agreement with a specific invoicer at the customer's online bank, and can set payment limits, notifications, and either automatic or manual approvals.

These are distinct from the "SEPA direct debit", which is not used in Finland domestically. Due to their rarity I think "SEPA direct debit" payments are usually/often disabled or each payment requires a specific customer authorization via their online bank (so IBAN of such an account cannot be used to get money out of the account).

How so? Avtalegiro is offered by the creditor via my bank. I click a box to allow it and I can also specify a maximum that they are allowed to take. Every time the creditor requests a payment I am notified before it is paid. I can cancel it or in some cases, such as a credit card monthly payment, alter it.

I can't stand it. Amex have implemented Express List to deal with this, and you can automatically add any new sites that you use your card in to the list. It doesn't even automatically trigger 2FA.