Few if any crew use ANR any way as all modern aircraft have both passive and active acoustic cancellation and damping in the cockpit
Exactly the opposite, in my experience. Of circa 850 pilots in our company I'd say we have 800 using ANR. Not sure what the other 50 use but there have been some compatibility issues. Our spare flightdeck headsets are about 50/50 split but going towards ANR as the old ones die out.
Couldn't live without mine. 2 x 6hr sectors per day will rapidly wear you out without good ANR. Maybe 757/767/321/738 are not 'modern'?
Bose-X leaves my ears quite sore, though.