> modular iphone that has an easy to replace battery, easy to replace screen and is maybe 2mm thicker to account for it? That would be a sellout.

Go the other way. Hermetically sealed, no connectors, inductive charging, rugged, with a solid state battery that will outlive the rest of the phone. Solid state batteries are more expensive, but that's a cost issue for car-sized batteries, not phone-sized batteries for US$1000 phones.

Samsung expects to have 20-year battery life in 2026.