I do a lot of online banking, etc I’ve got a new model of iPhone currently- only 5 months old - so luckily don’t have many worries at the moment.
However, with my previous iPhone, bought early 2017, I found that gradually after about late 2020, the apps would gradually become obsolete aback couldn’t update them because I didn’t have the required, up to date enough version of iOs.
I remember- first of all my email app went, then my main banking app, then Twitter - and a lot of websites I just can’t access. The ONLY internet app that’ll work on it now is a very old version of Facebook. Not even the App Store or iTunes works.
None of the old store apps work on it like M&S or Nectar.
it was so inconvenient aargh!! Especially when I don’t have a PC or broadband in the house - it was my only internet source.
The main things I use my old 2017 phone for now are:
Facebook
Youtube
Wikipedia
Geograph