I do not own an HDR display. I agree that HDR has huge advantages, but it costs money, and little of the content I consume is available in HDR.
The cost of HDR displays is decreasing, and the data cost is minimal. (adding more bits to video actually decreases the size because the rounding errors get smaller)
If I had a black and white tv, all my content is there, how would I know if they had color versions?
Ok, a little over the top on the last one, but still correct.