The irony of this is that when using Firefox to browse to /e/OS url to check for compatible devices:

https://e.foundation/installer/

I get a pop-up telling me that my browser is not compatible, and I should use Edge, Opera or Chrome. See [1]

[1] https://imgur.com/a/al1Q9DM

Yes fortunately we have browser alternatives.

But on mobile, my bank and my government force me to use the Android/iOS duopoly.

Chrome is just an example. Google stopped pretending Android is a general purpose OS and started cracking down on what is possible without Google’s approval. See developer verification, everything within Google services, etc.