> My PC has had a scanner connected to it for over 20 years

You're basically the only person in America doing this. Tens of millions of folks are just scanning it with the app on their phone and it's objectively a much better experience lol. The resolution of the photo taken on your smartphone is beyond good enough, there's no need to over-engineer something here.

> You can't invade the user's privacy nearly as well in a browser (which is great for analytics/marketing), so there's a lot of incentive to the app creator to force a mobile app. But I think we should be honest that it's not for the user, it's for the company.

I agree with your first sentence, but not your second one.

Banking applications can certainly get more/different data on you from using the app, but the job of the bank is to protect money and to know their customer. Privacy is secondary, of course outside of things like other people knowing your account balance, unauthorized access, &c. That's for the bank, because they don't want to lose your money, but it's also for you because you don't want other people getting access to your money.

Make that two people. I much prefer to slap the rare check on the scanner than fiddle with the phone. My banks "scan the check" part of the app was buggy for a long time, so maybe that jaded me. (~"move closer", ~"move away", ~"increase lighting"...)