Paywalled article, but in a nutshell:
“a new set of data from mobile data analytics company Ogury, which analysed the mobile banking behaviour of 688,000 people in the UK between 1 July and 30 September […] suggests the old high-street lenders needn’t be getting too worried just yet […] traditional banks not only still have a much larger share of the market, but also a far more faithful customer base – at least in the sense that the majority of their customers don’t use other banking apps”
As an example (it’s not critical of Monzo or any Fintech):
“Monzo’s exclusive customer base, while the highest among the challenger banks, is only 20 per cent, or less than a third of Barclays […] It is the biggest challenger bank in terms of market share, though its monthly active users were less than a quarter the number of Barclays’, at 6.2 per cent compared with 25.2 per cent for the traditional bank […] the top three apps that Monzo shares its customers with are Barclays, NatWest and Halifax”
The article makes several other relevant points – for example noting that the survey only covers mobile banking, not online banking generally, and that the fintechs have a much younger demographic that could turn into increased market share (68% of Monzo users, presumably extrapolated from the sample, are aged between 18 and 34).