You'd need to make a case that proprietary OSes such as Windows or MacOS lessen the issue compared to FOSS OSes such as Linux. I doubt it considering that Windows is / was known to be the worst offender here.

In any case my bank has not banned the use of Linux to do homebanking. Why? Because there isn't a easy to plug-and-play API to do DRM and remove consumer rights. This is largely for historic reasons, but there is no reason a FOSS mobile OS couldn't work.

In all fairness, a FOSS mobile os does for the most part work. Banking is pretty much the only big mainstream acception here. Most other exceptions are games with aggressive anti-cheat, or app simply not distributed outside a closed down store like Google play.