That seems a very sensible use of your iPhone there. That Wi-Fi calling feature is handy for sure.
Regarding that app ecosystem, that's the thing. Apple keeps an iron grip on what's allowed and not allowed on their platform, so if they pull an app that I was using, or don't allow a certain type of app, then I'm out of luck and I really don't like that. On the plus side though, an iPhone app is very unlikely to contain any sort of malware in it and if it data mines you it will more likely be disclosed in the product description, which leads to peace of mind which is equally important. Hence, I reluctantly accept Apple's control over the apps.
Those people who root their phones tend to be the younger generation I believe, who are more likely to take risks in life and perhaps a good dose of ignorance helps, too.
I actually wanted to upgrade to an iPhone 13* of some description, but there wasn't one that met my requirements: a perfect, rectangular screen that doesn't have a maddening notch in it. They sort of do have one, effectively an upgraded iPhone 8, but it's not the Plus size that I want, so I couldn't go for it, unfortunately. Of course, I'll be forced to upgrade when the OS updates stop coming, but that should hopefully be ok for a while yet, although my model is now 5 years old, so coming near to the end, unfortunately.
*For the most nerdy of reasons: 13 is a prime number, it's considered to be a "lucky" number in maths circles and it freaks out the superstitious. This last especially, lol.