Final are interesting - I do agree that there is a problem with cards but not sure I’d describe it as ‘broken’.
The thing that really matters here is whether there is a sufficiently large market of people for which current card behaviour is such a problem that they are willing to:
a) Consider generating a card number per merchant and
b) Consider switching to a card that allowed them to do that
Personally I’m not sure there is a market there. Just because people have a problem, doesnt mean that they will actually act on it. There will definitely be a set of people that Final will be very appealing to, but will it appeal to a large enough market to make it a successful proposition?
What really matters here is what drives consumer behaviour - its not sufficient to solve a problem - it has to be a sufficiently important problem/unmet need to actually drive action