They have about 25 million customers, which would be about 5% of the EU population. Meanwhile about 38% of Europeans own a credit card [1].
Revolut is growing rapidly, so I assume there are plenty of bubbles where revolut is more widespread than credit cards. But the near-universal scheme in the EU would be sepa direct debit. And while the lack of instant confirmation is a drawback for online purchases, that shouldn't matter for something like GitHub Sponsors.
This is entirely a Dutch issue. Their banking system is extremely weird and they consider Visa and MasterCard to be credit cards (even if it literally says "DEBIT" on the card itself), and thus they aren't accepted in a lot of places, only Maestros (which don't work for everything) are. Thankfully that's changing now and my recent trips there didn't require keeping cash to pay.
almost every bank in almost every european country issues Visa/Mastercard debit cards that can work for ~everything that claims it wants a credit card.
I just checked all of my German debit cards and they're all Maestro, not Mastercard/Visa. So that's already two countries that don't typically issue compatible debit cards, not to mention the low penetration of credit cards in Germany, too. I probably know more people with PayPal accounts than credit cards.
I lived in Poland, Finland, UK, the Netherlands and Germany. Never had an issue pay online with a card since early 2000s.
There are two types of debit cards.
1. The legacy Bank Cards (think EC card in Germany) and
2. The "new" (I say new, but they have been around for 20 years) debit cards, which looks and act like Credit Card, but do not give you line of credit and requires fund on savings/current account.
Except for German Sparkasse (not a real bank) almost every bank offers you option which card you want (Fidor even issues "Smart" card which is both, legacy and new Debit Card).
The Netherlands had time with this super wonky Meastro cards, but I hear it no problem anymore.
Some dodgy bank will ask for an extra fee, but most don't.
I had my first Debit Card for online payment, as a student in 2004. Yes, paying with CC/DC in Europe is not an issue.
It is not novelty. They are common. Your bank might have simply not given it to you.
All that said, if I can, I will ALWAYS pay with SEPA.
The idea of giving someone the key to your wallet for a fee (merchants pays the fee, but it is baked into the cost of goods) is so absurd that I can't event fathom.
My business, Wide Angle Analytics, uses CC and even allows PayPal via Paddle. But we explicitly state that you can ALSO pay via invoice, with bank transfer for any annual subscription.
I'll stop the discussion here because some regions do issue debit cards that are usable online like a credit card and are connected to Visa and Mastercard with 3DS and such, but other regions either treat that as a luxury item or requires you to pay a maintaining fee just like credit card (for Americans, yes in other countries even if you always paid in time there is still a separate maintenance fee) because they have local systems like Interac or iDeal that are operating indepedently.
