Moving parts and physical connections are fragile. Wireless connections solve that fragility. Agreed that pairing sucks, but that's a solvable problem.
The music industry standard for instrument cables is 1/4" TS for unbalanced instrument audio, 1/4" TRS for a few things like monitoring headphones, and XLR cables for most everything else. XLR in particular is a very durable system, unless you get a very badly made XLR cable or jack I would never call this system "fragile". Even 1/4" is quite an improvement durability wise over 3.5mm.
XLR is not exactly a very portable jack, but a mini-XLR jack does exist -- not as portable as TRS 3.5mm, of course. But if increasing jack durability is such a concern on a more portable device, this connector is an option. Same with using 1/4" TRS, this is a connector which has the advantage of having more headphone options with this option built in (most headphones marketed for studios should be 1/4" TRS or at least have that option).
None of the above are as portable as 3.5mm and I think this connector is "durable enough" to where I doubt it is such a priority for most phone consumers to give up some phone thickness for better durability. But in professional music applications there is a reason why 3.5mm is relatively rare.
I mean, at some level, come on and use your imagination. People riding the metro don't always have total control over getting their belongings situated properly when the train's packed and there's a lot of bustling around. I assure you this experience is not unique to me.
So, I guess there are tradeoffs -- and fixing pairing means everyone can enjoy freedom from one more wire, while keeping on using a wire means we keep adapting our behaviors around a wire.