Isn’t the problem Starling themselves say one card two accounts, so imply its all linked, so its not so much that it should be linked, but Starling make people think it is. When in fact its not really one card for two accounts, its one card you switch between accounts manually. That confusion will most likely affect lots of people, because people take things literally, and why should they not, after all its a bank.
Yes I’m aware people on this forum will disagree its confusing, but I’m talking about the general public. Not those with 10 FinTech accounts.