Shariah banks have to operate in a world that has completely accepted conventional banking. As a result, it is in a constant state of playing catch up in terms of fitting in (e.g. having to implement a software interface in which you reject some central tenets of the interface).
I don’t know the answer one way or another. What I do know is that conventional banking remains imperfect in spite of it being totally dominant: the boom-and-bust economic cycles have grown more catastrophic, and we are still grappling with accurately adding phenomena like health and pollution into our financial models.
I applaud you for trying to understand how conventional and sharia financial products fit together. I don’t find your reaction offensive: it just means we aren’t done trying find a good solution that makes both technical and moral sense.
There’s a really long Wikipedia article here about profit-loss sharing, which central concept of how sharia banking is meant to work: https://en.wikipedia.org/wiki/Profit_and_loss_sharing
N.B. I apologize for any typos since I typed/tapped this out on my phone.