People here seem to think this is some sort of Orwellian attempt to control them, but the reasons are more mundane and technical - many of them (mine included, from two countries) use security facilities on the phone to secure your accounts.
For example, my HSBC UK app has replaced the little calculator thing they used to ship, and uses iOS face recognition to secure the generation of log-on codes which you need in order to use the web interface, as well as for secure access to the banking app directly.
With a rooted phone they don't have the guarantees that these aren't being exfiltrated, or the app being subverted in novel ways, so they don't want to support it.
You may not consider this a good enough reason, and I have heard it said on HN that 'the banks shouldn't get to control what I do on my computing device!', and that attitude is absolutely fine, but then you'll most likely end up with either less secure banking (meaning more fraud, higher fees etc) or going back to having to have a dedicated security device.
> I can deposit checks through it on my laptop
American-like banking detected... who uses checks in 2025?! :)
Yeah, fair. :-) I live in a small town, the only check I write is my rent check, which I literally walk across the street to deposit. But I still on rare occasions receive checks as well.
I did receive one check this year, a refund from a company who had screwed up billing on a medical scan. For some reason they couldn't just refund it to my debit card. It was really annoying to have to get to a bank during opening hours to deposit it, but my bank here doesn't offer mobile check scanning. Some do, my old UK bank did ... oh well.