Earlier quoted context omitted.
Re: "Layout on the server means you're laying out without the context of my device or viewport" Why are you making that assumption? A device can either send its screen size to the server, or a size preference category if it wants to hide details: watch, phone, tablet, laptop, desktop, workstation. (And user should be able to switch the preference manually.) Re: "And like I said this resulted in a bunch of ridiculous…
I really don't think you have thought this through.
I have. Throw specifics at me. Bring it on! I've been in many debates like this before, and my suggestion is skeptic-tested.