I’m a data point in that: I bought a DSLRs and a few lenses probably 15 years ago. Over the years I used them less and less to the point that they’re gathering dust now. It isn’t worth the extra bulk when I head out the door, smartphone cameras are good enough.
If you're out there shooting a hundred basketball games a year or you're camping out in a swamp every weekend to get a picture of a bird it matters.
But that was never the majority of people buying "Pro" and "Prosumer" camera gear. For the vast bulk of the market the smartphone camera gets the job done at a fraction of the cost, way less stuff to carry around, and a much better workflow.
Too many hobbyist photographers seem to miss the forest for the trees here, no one cares about how sharp the picture is or how much dynamic range there is if the content of the photo isn't compelling.
But my experience with a Sony is that you need to do at least an auto-correct on Lightroom/whatever before sharing.
But an iPhone/Android is much much less conspicuous, which is a huge advantage for street photography.
The Olympus Tough series may be the last man standing in that category until Apple makes a shatterproof and diveproof iPhone.
Pentax has bucked the trend and has continued to release new DSLRs as recently as this year.