Good plastic is not flimsy.
Polycarbonate, an almost commodity plastic, is really strong and light. The next step: composites are way better than any metal if you want a good strength-to-weight ratio. The best, most expensive bikes are made out of carbon fiber composite for a reason.
Plastic is commonly used as casing material for stuff designed for rough environments. Portable power tools, PA speakers, even guns. So if something designed to be used on the battlefield can be made of plastic, there is no problem for headphones worn, at worst, in the subway.
The only problem with plastic is that it suffers from being cheap, as in, not expensive enough. People want expensive products to be made of expensive materials. Also, subconsciously we associate weight with quality, so much that cheap manufacturers sometimes add metal inserts to their otherwise low quality products to trick people into thinking they are better than they really are.
That it to say, unless you put a premium on look and feel (nothing wrong with that), don't hesitate to buy plastic headphones, they can last you a lifetime as long as the right plastic is used at the right place.
However those cans don't have bluetooth, noise cancelling, a microphone nor adaptive EQing. They're literally just a high quality speaker, headband and copper wiring.
By contrast, the Bose and Sony headphones, which feel more flimsy in comparison, I can wear for hours without issue.
Also to consider, AirPods Max can be extremely well built but you still cannot pack them in a suitcase like you can the Sony or Bose, due to the shitty pouch that’s included...
It's a non-issue.
Indeed a non issue (assuming you also own a money printer).
https://www.macrumors.com/2020/12/08/airpods-max-shipping-es...
That said, the B&W v-shaped sound is not my favorite. Not unlistenable, but maybe not what I'd choose again.
This has always surprised my as someone who's owned a couple of pairs of B&W P-series headphones (P5 then PX). Portable headphones should be built to last, not just flimsy plastic. B&W got it right with metal construction (and with the newest PX models forged carbon fibre), no surprises Apple is building robust headphones too.
What B&W provide though, is a really solid benchmark (of many) (with the exception of spatial audio - which from Gruber sounds like it still has some shortcomings to overcome). They're £200 cheaper, really substantial and solid construction (with a proper hard carrying case - although similar limited folding), the newest carbon models will be noticeably lighter (if still a substantial 310g).
Obviously the Sony XM4s and Bose 700s are well in view too (although plastic construction can make them seem a less premium alternative).
I expect these will sell relatively well, but I can't see them flying off the shelves like their in-ear namesakes in such a crowded and competitive market, even with Apple's software bonuses.