Wax jackets are okay. They have their advantages. They are a bit more resistant to barbed wire, compared to a lightweight Berghaus jacket (other makes are available) that tears as soon as you look at it, but not even a waxed jacket is impervious to the dreaded barbs. It's got a fair chance with gorse bushes though.
No, the main drawback of wax jackets is their breathability properties. Which are on a par with bin bags. So not really the thing you want to wear where any walking is more than a saunter of a hundred yards or so.
However, they can be smart, or completely the opposite of smart, so either way, they can be a fashion item. Which possibly drove Barbour to outsource their manufacture. Simply because as working clobber, once waterproof, breathable and still robust jackets came along, their use as serious outerwear for the more mobile person was pretty much over. Over the last few years, fleetingly or otherwise, I've been involved with five pheasant shoots. And amongst the guns, beaters, pickers up, landowners, and other sundry characters, not one wax jacket was to be found.