Yeah I have to agree, the financial cost is tiny. The physical packaging cost is high. If you see how dense modern devices are, and how much space modern cameras take, you can see what the cost of taking the equivalent space of a 3.5mm jack is. Ingress is an additional valid engineering problem.

Don’t get me wrong, I wouldn’t mind devices that are a few mm thicker and therefore have less packaging constraints for jacks, bigger batteries, etc.