You're not wrong, but I have to wonder how much phone RAM is just the new megapixels, i.e. bigger number = more impressive spec sheet.
iOS is obviously a lot stricter on background activity than Android but manages to work great on 3-6GB.
I can comfortably do development work on my laptop with 16GB, and until last year was managing mostly okay on a 5 year-old machine with 8GB.
When you factor in the sort of stuff people actually do on a phone, surely 12-16GB is a massive waste? You can make the argument that it will become more useful as the phone ages, but by that point it will have probably stopped receiving software updates.
True, my 3 year old phone has 8GB ram. On a laptop, 8GB is just anemic.