The title mentioned lending, but the article says almost nothing about it.

As other commenters have noted, these new banks often have great customer experience. But they don't do much lending. For example, as of February this year, Monzo's loan book totalled 160,000 GBP [0]

Disclosure: I co-founded a UK-based fintech lending business (www.oakam.com). We're hiring PMs, Data Scientists and Software Engineers. Message me if you might want to work on expanding access to credit, and increasing financial inclusion.

[0] https://monzo.com/annual-report/2018/ (ctrl+F 'Loans and advances to customers')