Let us not forget that S7 and S7 Edge had headphone jack and were waterproof.

Not user-disassemblable, much less Lego-style modular, though. Easy to make something “waterproof” when you can just seal it shut with “gooey black adhesive”.

I personally think the headphone jack is a wonderful truly universal and effectively completely open standard that’s very good at what it does, and which furthermore is doubly useful as a generic power and analog signal delivery mechanism, while mandating its supposed successors like Bluetooth and USB-C needlessly and massively inflates the technical and material cost of just playing a dang sound file. You could get serviceable wired headphones that last forever for like $5 if you were lucky; Nowadays, you pay at least ten times that for fragile lithium batteries and circuitry that will break in a couple years, and I really don’t like this trend of taking away capabilities for less robust alternatives while portraying it as innovating.

But I also actually use my Bluetooth headphones way more than my wired ones, and I appreciate the potential engineering and market challenges in what Fairphone is trying to do here.