I mean I expect devices and apps to move to DoH, but they haven't yet, or at least not all of them. My experience generally on my phone at home (with DNS blocking) is better enough than my experience away from home that I'm glad I took the half a day or there about to set up a DNS blocking tool a couple years ago.

A couple years ago it was like night and day. Now it is still better than nothing, and in a year or two it might not be worth running.

It's definitely a moving target, but "we expect ... to move to DoH resolution" means that they haven't all moved yet, and a DNS based ad/telemetry/etc blocker still works today (for some apps / smart devices). If it works for some things today why would I turn it off because it might not work for a subset of those things tomorrow? Agreed the value proposition of setting one up is probably dropping, but I still prefer it to nothing.

Now that I think of it I should probably start logging how many DNS look ups "fail" because of the DNS blocking list, and monitor for changes. If it ever gets to less than one a day it's probably not worth the couple of W to power the RaspberryPI