It is one of those things I wouldn't believe if I hadn't seen the data. You would think the people still buying physical media are collectors and collectors would opt for 4K Blu-Rays, but I guess the technology barrier still exists for older people with streaming?
i started buying bluray a few years ago but i didn't stop buying dvds, i've only slowed down a bit because i've been spending a lot more on cds/vinyl, mtg/lorcana cards, and graphic novels/comics issues recently. if i'm buying new i usually go for the bluray if i really like the movie but if i'm buying used i take whatever i can find in the store. i don't have a proper bluray player, only an external drive i plug into my pc (or my laptop, which i then plug into my tv). most of the time i'm using my dvd player to play my cds, it's not actually connected to a display.