I've lost iPhone access to Chase Bank and Discover Card because their apps have been updated and can no longer run in my iOS 12.x.

Why can't these mobile apps either be updated or backwards compatible, same as my desktop apps?

Thanks.

Isn't that a question for Chase and Discover?
Why can't your iOS be updated?

(I am guessing your iPhone has the A8 or earlier processor which blocks your installing iOS 13 and later? )

Is it possible the Chase and Discover Card apps are relying on iOS security features that were not available in iOS 12 and earlier? I have noticed a recent spate of security changes/enhancements on financial sites. The internet is an increasingly treacherous domain.

My phone is a 5S. It's maxed out at iOS 12.x.

It's a question for the apps' unreachable developers, not its customer service reps.

My phone is a 5S. The A8 first appeared in the "6."

It's possible, perhaps even likely, but why can't the apps be backwards compatible as they'd be in macOS?

I'm not so sure those apps would be a full decade backwardly compatible in macOS. I'm running High Sierra, which is a bit more than 5 years old, and receive "your browser is obsolete" warnings from multiple financial sites. So far, they continue to be functional, but it's clearly only a matter of time...

I bought my iPhone in Nov 2019, so I've always tended to think of it as a fairly recent model, but I just checked Mactracker and found that its production run was from Sept 2013 to March 2016, which makes it "Vintage," soon to become "Obsolete." (It's original iOS was 7.0, and it maxed out at 12.5.6.)

So, rolling it around in my head, I'm realizing that I can't equate iOS apps with macOS apps: in macOS, an old version of an app can run in an old version of the OS because it's "self-contained," but the iOS apps with which I've run out of luck are kinda like a cross between an app and a website, and an old version of the "app" can't connect with the new version of the "website."

Does that make sense?

I can, of course, still access the Chase and Discover websites via Safari, but not necessarily get the same functionality as I'd get with their apps.

Yeah, so the iOS is updated (upgraded) when you get a new phone. Same as my desktop Mac. I've purchased new Macs when the old one still worked, but apps, usually Safari, no longer performed up to my expectations and could not be upgraded because the OS could not be upgraded. I expect that will happen with my iPad someday as well.

Sandboxing does not mean an app cannot use or be dependent on API (Application Program Interface) functions provided by iOS/iPadOS/macOS, it means the apps have no mechanism for accessing data or functions in other apps. In fact, those APIs are essential for the apps to function. I don't know about the Chase or Discover apps but since they access the internet and are likely dependent on JavaScript and HTML code it is just about a given that they both use APIs provided by the copy of Webkit in Safari. athe last time I checked, all browsers, Mail and similar internet apps on iOS, including Chrome, Brave, and even Firefox, use Safari's Webkit instead of their browser engine they use in macOS. (BULLETIN: Mozilla is reportedly working on a non-webkit version for iOS)

And yes, it does make sense that an old version of an app or iOS cannot properly interact with the latest version of a website. There is no backward compatibility requirement in the W3C standards, governing HTML and JavaScript, so a site using a newer version of HTML or JavaScript may not work with an older browser engine version that does not know how to interpret the new or revised site code.

Thanks for that.

I'll NEVER fully understand what's going on under the hood...never even get close, but your patient explanations always help get me closer.