True, bank are using stupid rules sometime. I had a revolut account before switching to /e/os deleted it because of this. This was not my main account and I dont have issue with the other bank apps, so I can understand the problem.
That said when you are switching to a custom you'll always have some limitations you just have to know were you set the bar, and this is really personal choice.
I don't understand why most people consider that having the bootloader locked is so important. You'll get a terrifying warning message when you start your phone. But without a physical access to your phone and your password, no one can do anything.
So you consider France a communist country ? I dont get it