Yeah, likewise the Breitling Emergency is big because it's an actual working 406 MHz Personal Locator Beacon. In principle that's all you need to have a rescue team come get you if you, I dunno, crashed your plane on a desert island or you broke your leg while hiking in Siberia, or whatever. Of course if you're the sort of person who wears a wristwatch which costs as much as a car you probably aren't doing anything like that, but you could be and maybe you're an elite solo who "travels light" and so you couldn't pack a conventional much cheaper PLB.

I can't imagine Breitling sells very many of these, they're huge heavy watches, if you're The Rock they probably look fine on your arm but the average tough guy can't justify owning a watch this expensive and if you're the 5'4" female CEO of a famous company you can afford the Emergency but it looks ridiculous and feels like you're carring a boulder on your wrist.

Like Concorde, sometimes we prove something was possible but it turns out it was unavoidably too expensive and annoying for it to make much sense in the market.

[Edit: Fix spelling of Concorde]

Sadly, no major miniaturization breakthroughs since. And those CSACs still eat up a lot of power (as do good OCXOs), making them rough for battery powered wearables.