Look, this effort was only necessary because of this whole girocard mess.
But obviously both Apple and the Sparkassen thought the effort is worthwhile.
I think it's about scale. Sparkassen have 46m Girocards out in the wild. With a market share for iOS of roughly 22% percent this makes 10m cards. I do not believe any other banking group in Germany or Europe has that kind of scale.
Again, I am not saying that Girocard is a perfect thing technically. It probably is the opposite. But quite frankly, most people do not care. And even I - with some understanding of technical backgrounds - are intrigued by the advantage in acceptance.
Girocard is hard to beat in germany because of
a) acceptance [755k merchants vs. 500k for MC/Visa] and
b) transaction fees for merchants [the merchant pays ca. 1% for Girocard vs. ca. 2% for MV/Visa transactions] and
c) penetration [in Germany 95% of the population has one and most use it frequently].
This combination is pretty hard to beat as I can not imagine that MC/Visa will half their fees which would be the starting point to break the acceptance barrier and the banks will not offer MC/Visa credit or debit cards for free as they have to pay licence fees to MC/Visa which they do not have to pay for their girocards as it is based on the German banking infrastructure itself.
Yeah, I know about the acceptance problem. But that is the core of the problem - it would be a lot easier for everyone if we would use some compatible system instead of our isolated German girocard.
What would be a lot easier?
Are you seriously proposing of using just one card? That's fine if it works out for you. But it would never work out for me.
I am using several different payment cards in order to separate business and private expenses. Also with MC or Visa you can occasionally run into acceptance problems when traveling internationally. That's why I love to have a backup card. And I don't mind adding one more to my Apple Pay wallet. It is not so burdensome to switch cards if someone does not accept your default card.
I like choice and I like competition and in that sense I like Girocard as well.