It's more that they want to disaggregate the customer service and tech stack responsibilities from the financial ones, with the profits split accordingly. At least in the US, Chime and other "banking fintechs" do have real banks underpinning them (The Bancorp Bank and Stride Bank, in Chime's case). This new the three-way relationship (customer-"fintech"-bank) can present new types of risks, and there's definitely room for overhauling the rules that regulate it, but it isn't an inherently bad business model.