The thing becomes useless as soon as it stops getting updates, because your browser doesn't get new features and gets locked out of various parts of the internet as time matches on without you. On any other computer, you can keep the browser up to date long after the OS stops receiving patches.
Not sure why I'm getting downvoted. The Chromebook Pixel was an awesome home computer until it stopped getting OS updates, which also pinned it on a version of Chrome that got obsoleted from the web. (Unlike IE, nobody cares if something works in old Chrome, and some sites actively reject old versions for security reasons.)
https://arstechnica.com/gadgets/2023/09/ios-16-7-arrives-for...
Could you update to iOS 16.7 and check which Safari version it uses? Would be interesting to know. On macOS you can already install the newest Safari version even when running 3 year old macOS.
What I really want is an up-to-date browser even if iOS stops being supported on an old phone of mine. (And they seem to be dropping support faster, what with iOS 17 not supporting the iPhone X — introduced in 2017 — without any legitimate hardware reason.)
It's ridiculous that Safari and the underlying WebKit engine only get updated with every accompanying iOS release.