I have a couple of thoughts to offer. First, in my world of education, I have seen the "pendulum" swing back and forth so many times, so when a "radical or different" idea comes across, especially if it is lacking common sense, just wait a few years and the "radical / different" pendulum will swing back. The downside is that it often doesn't stop at the neutral spot and continues to the other extreme. But, not to worry, it will swing back. Example: conventional classroom, one teacher and a group of students ... then "Open Space" moves across the country, usually west to east, resulting in four teachers, four groups of students, all in one large "classroom pod" configuration. Then ... educators realize it was a bad idea, then spend millions retrofitting those "Open Space" back to the traditional setting ... can you imagine? ... one teacher and a group of students. That has gone on for the three decades I taught high school, and I continue to see more changes in high schools, thankfully I am now teaching college classes.

I'm very confident this will happen in the photography world.

AND, about film? Our university has offered degrees in photography, to include both digital and film, complete with darkrooms. Over the 22 years I've been teaching college classes, (physics not photography), I've observed that enrollment has never flattened, and continues to increase.

Unusual anomaly? Remember the LP records? They haven't disappeared either. In fact, in the UK, I've learned recording stars insist their releases be offered three ways: (a) download, (b) compact disc, and (c) on LP vinyl. LP record sales also have increased in the USA for the past ten years. You did notice, didn't you, the (b) option was ... CD, standing for compact disc?

So I have not a single doubt that our DSLR (w/mirror) will continue to decrease. After all, the big camera makers must "improve the mouse trap", hence mirror-less. But DSLR, w/mirror or wo/mirror, will never disappear. In fact, I predict that sales will spike upwardly again, with aspiring photographers will bring it all back by 2030.

On that note, I'll tip toe out of here with my two 5DII bodies, three L lenses, and plan to continue shooting far into the next decade.

I don't think so. Perhaps tunnel vision plays a large role in defending DSLR's. I have one and I use it. Not a lot. No matter where you go today here or abroad cell phones rule. More people use those than DSLR's. When those younger users have a family/children their children will know of nothing other than cell phones. There is no need for them to progress to anything else. They will not be aware of "real" cameras there is no need for it. If you use a DSLR I don't think there is a need to belittle or demean a picture or a person with a cell phone. I don't understand the need to do so
In closing I will say my wife wanted to go to the camera show in NYC. She went there I went to MOMA and we met for lunch. I arrived first and when she came in I knew something was afoot. She bought a Sony A7R111 and a lens. I said nothing just ordered another drink. I wonder what she will think when I get my new Audi in December?

What?

“In 2014, according to Mary Meeker's annual Internet Trends report, people uploaded an average of 1.8 billion digital images every single day. That's 657 billion photos per year.”
Source: https://www.theatlantic.com/technology/archive/2015/11/how-many-photographs-of-you-are-out-there-in-the-world/413389/

“Estimates suggest that more than 1 trillion photos were taken in 2018.”
Source: https://theconversation.com/of-the-trillion-photos-taken-in-2018-which-were-the-most-memorable-108815

Cameras are not disappearing. To the contrary, cameras are increasing in number. Almost everyone has a camera today. Some have more than one. They have just changed shape.