I think the lack of an off button is a feature, not a flaw. I've got the Bose 700 and they are a nuisance to turn on and off, and for what? The Max just works -- put it on your head, take them off. Simple. 20 hour battery life means they will last for a long time even with the 3% or so drain every night. BTW, the Bose drains battery too even when off. And it is just yet another button to push -- along with all the other fussy features of the Bose 700. I am so grateful never to hear that repeating "ready to pair" drone from them again!
This.
We don't turn off cell phones anymore. Same with laptops. Tablets. Watches. Wireless keyboards. Wireless mice. TV remotes.
Now this feature came to headphones. Wait a year or two and I'll bet ALL wireless headphones will get rid of the off button.
Mine use about 7-10% per day when not in use (extrapolated from about 3-4% per night). So this is 10 days (without the shutdown after 72 hours, which happens if you don't use them at all), pretty much ancient Nokia 6310i battery territory.
So it all boils down to:
1. You use headphones daily, either in long sessions or you put them on and off often. You charge them every 2-3 days. Benefits of not needing an ON button are obvious.
2. You use your headphones once a week. Either you use the bra and charge them once every 2 months or you don't and you charge them 1-2x a month.
Seems like a good compromise for not needing to fiddle with another button with a single functionality.
(think of yourself 10 years ago, when you struggled with how to turn that iPhone OFF during the night and you couldn't easily)