Banks don’t do this because of profit. They do it because of decades of laws pushing in this direction. Anti-money laundering, know your customer, digitalised currency, abandoning cash, preventing tax evasion etc… it’s been getting more extensive over time.
None of the things you mentioned inherently require the user to own (and babysit) an expensive general-purpose computing device produced by tracking-obsessed adtech giants and with software obsolescence built into the product.