On Thu, 11 Jan 2018 13:53:44 -0500, nospam wrote:

The user experience is *definitely* impacted when the phones shut down.

which is why apple has taken steps to avoid that from happening.

Indeed they did!

"Apple intentionally pushed iOS updates, including but not limited
to iOS 10 and 11 and their variants, despite knowing that the
updates imposed performance demands that the phones' hardware
could not meet, throttled the phones' performance, and otherwise
negatively impacted the performance and utility of the phones,"

http://www.zdnet.com/article/iphone-throttling-class-actions-pile-up-as-apple-hit-with-32nd-lawsuit/