You can check this list to see whether a particular banking app has been tested. It seems to me that most of them work and that efforts are being made to fix any problems with certain problematic apps if and when they are discovered. It may be that some app providers still try to block users on platforms other than the major ones, so the risk of failure is probably slightly higher than if you use Google’s Android or iOS. The one banking app that I need to use a few times a year has worked flawlessly on /e/OS so far (admittedly just for a few months and a couple of updates; I installed /e/OS in December 2024).