ETA: I am not a good investor, so this may make your point, but I would not sign up for owning a mortgage lending bank. I purposefully don't invest in any banks outside of being invested in them through S&P 500 funds. Just doesn't seem like a great business. Seems like the banks that grow fast usually do so by taking on extra risk or overpaying for acquisitions and I just don't like them in general as an investment class. That said, over the past 10 years, the S&P has outperformed the Dow Jones US Bank index by more than 3.5% on an annualized basis, which is obviously huge. But over the past 5 years, it's almost exactly the opposite, with the Bank index outperforming by a little more than 3% annually.
https://www.spglobal.com/spdji/en/indices/equity/dow-jones-us-banks-index/#overview
But I don't think it's the type of business if you told people that they had to pick something other than an index fund, it's a compelling investment that a lot of people are going to jump to. I'm sure plenty would just because banking is so visible to them, but I think they'd lag significantly behind people investing in tech stocks and probably oil and gas although I'm much less confident about that one.