I still have an iPhone 6 around somewhere which I mainly use as audio recorder (still has the 3.5mm jack, don't like the fiddly 3.5mm to lightning tail to plug in a Rode Smartlav mic).
Once I find it I'll see if it updates (as you can tell, I don't use it that often, it's buried somewhere with the audio gear as I now mainly use the Rode Go II. As it's 8 years old I think Apple can be forgiven for no longer providing updates, though, it has already had pretty much double the update lifespan of everyone else. Besides, all I use it for is the Rode reporter app and Wifi for transporting the resulting files and I'll keep doing that as long as the battery lasts and that is weirdly not gving any sign of retiring just yet. I think it's just being stubborn.
Like its owner :).