[CountSessine]

They have all their photos since 2010 stored in there and have inherited all the crap from every single unexpected reboot, failure and app residues, building up gb's of 'other files' as shown in iTunes

Meh. They should just copy their photos off their idevice using USB PTP mode. That's USB config 1 when an idevice plugs into a PC. No macOS required. No iTunes required. Done. Solved. As for the crap, isn't that an argument to NOT migrate via iTunes?

Most of iPhone users have a 5Gb iCloud account where not even a whatsapp backup fits, and they still need a computer to migrate all the data

ICloud storage is super cheap, especially compared to the price of a smartphone every 2 years. If you're not using this, you're cheating yourself out of one of the biggest advantages that iOS has over other computing platforms. iCould backup is the one thing in iCloud that really just works.

Plus there's dropbox. Solved.

But it still isn't strictly necessary.

That, and the fact that you're still unable to put music inside an iPhone if you don't a) buy it from the app store or b) using iTunes

Wat? Who still does this?