iOS 11.2 killed my IPhone 6S+, I have replaced the lightning port (just in case, even though it was clean) and the battery for a genuine Apple battery and the handset is kaput, it wont charge nor power on.
It turns out from research and watching a few Louis Rossman videos that it's most likely burned out the silicon in the power/charge IC on the phones' board - something I have no tooling to be able to replace, let alone any available spares to replace the chip with.
Thankfully most of my data was already backed locally up via itunes, I create a backup whenever I plug my phone into the PC/itunes which wasn't too long before Apple bricked my handset, so I restored onto a new iphone 12 and grabbed the rest of my data from the cloud.
All in all it was a complete pain in the arse experience, Apple Support did reach out on twitter offering the usual "send it in and we'll take a look*" (* and charge you exhorbitant fees for each component that needs replaced), given its the power IC they'd most likely replace the entire board, the same board which has all my data stored on it. So I would in effect get a repaired / entirely different handset back without my data onboard along with a large bill.
In any case I opted for the more future-proof option of a new handset. Some of you will be asking why go back to Apple - better the devil you know, I've never liked Android nor trusted Alphabet/Google, if Blackberry were still making their own handsets with their own OS I'd have jumped back to them.
So for anyone saying the accusation that Apple deliberately release software updates that throttle and/or brick older handsets is false, you are talking bollocks.