The + of PayPal was in 2005 when you could use it to hide your card number from the merchant.

But now, you can generate one-time use cards, which are safer than assigning a card on your PayPal account.

The other thing, is that you can do chargebacks more easily, when you buy on eBay, but this comes at the cost of higher fees (which is basically insurance)

Other than that, it's a platform that cannot be trusted

I can't speak to how other European countries did only payments, but you never gave your credit card number to the merchant in Denmark. It was always done via a 3rd. party payment provider, initially mostly DIBS, then came WorldPay and later many more.

Charge backs was also always fairly easily done via your bank. Though you did have to call them, so yes PayPal was/is easier. I don't know, the trust in PayPal was always really really low.

It was before 2006 (enforcement of PCI DSS), at that time, a lot of merchants just created and hosted themselves a payment form and stored bank card numbers themselves, numbers that they often collected on non-HTTPS pages

Because the banks are liable to fraud in Denmark, probably also other countries, they already had really strict rules for online payments. Denmark also has it's own national payment card "Dankort", and before 2006, you needed to accept Dankork as it was the most popular debit card. The Danish banks could make their own rules, separately from PCI DSS, and those where much stricter, so no http and only specially audited software was allowed to handle the transactions. The downside was a near monopoly from DIBS.

I strongly disagree. The main advantage of Paypal and the reason for its popularity in Germany was the fact that it provided instant payments at a time when credit cards were very uncommon.

Cash on delivery was a huge pain since you had to potentially large amounts of cash ready to hand over to your postman upon delivery. That's the opposite of convenient.

Alternatively you could pay by bank wire transfer, which of course led to an additional delay of a day or two until your transfer actually arrived at the sellers bank account. Nobody wants to deal with barriers like these in ecommerce. Paypal was a godsend back then. Remember, barely anyone had a credit card in those days in Germany.

At the time PayPal rolled out, the single feature that made it popular in the USA is that it provided eBay sellers an easy/cheap way to receive credit card payments from buyers. That is all. Any person could set up a PayPal and instantly start receiving credit card payments without setting up a vendor account with a credit card company (which was not trivial at that time).

Right. But that was only relevant because US customers wanted to pay by credit card (because of some combination of credit cards being good and other payment methods being bad in the US). Which was not the case in most of Europe.

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.