The "global" is the problem here.

Each country had a local solution. Direct transfers, or better direct debit, was the common way in Germany. You literally just entered your bank account number and that was payment, the seller would debit it from your account. Zero authentication, and it worked - never had a fraud issue (in the background, I assume sellers checked the delivery address against some database before accepting this, as the seller would ultimately be on the hook for any fraud).

Aside from manual bank transfers (seller ships when the money arrives 1-3 business days later) there were also two systems based on direct bank transfers. One (Sofortüberweisung/Sofort) was essentially institutionalized phishing - you give a third party your banking credentials, they log into your account, snoop around a bit, wire the money to the merchant using your credentials and confirm to the merchant that your account has enough money and the wire is happening. The other was a similar service but by the banks, so you'd log in directly at your bank to authorize the transfer.

Most other European countries had other local systems that covered this need, but there was nothing global. Globally, your best bet for small amounts is unfortunately likely still PayPal unless your counterparty accepts crypto. For bigger amounts, there is Wise and similar services (note that I've had a horrible experience with Wise - KYC asking for things that didn't exist, luckily before they had my money to hold hostage). Wiring directly to accounts with Revolut also works reasonably well.

For transfers within the Euro zone, a regular SEPA bank transfer is easiest, with the only "downside" that you need to ask for the destination IBAN rather than just a phone number or similar that some of the other systems support.

Global scale is different indeed.

EU scale there are tons of solutions: iDeal (expanding to EU from NL), Klarna, sofort..

You're probably referring to historically, but if not, it's worth noting that Klarna bought Sofortüberweisung

Yeah, one could hope even more. E.g. MobilePay in Nordic countries take big fees because (based on my limited observation) most people just put their Visa/Mastercard in there.