Absolutely. For example, my parents in law, who are very much non-technical, had a Canon DSLR, and a film SLR before digital, that they used to take normal fami

Absolutely. For example, my parents in law, who are very much non-technical, had a Canon DSLR, and a film SLR before digital, that they used to take normal family/vacation photos. They've long since switched to just using their phone. I think you're underestimating the number of people who bought low-end (D)SLRs with the cheap kit zoom lens and used them for regular, non-enthusiast, non-professional photography without ever taking the lens off let alone buying higher end ones. The alternative used to be a compact or bridge camera without an interchangeable lens, and those too have gone close to extinct. Essentially, the market served by (D)SLRs has changed to be almost entirely pros and dedicated hobbyist photographers, which is a small market compared to "everyone who takes photos". And now, mirrorless is well on the way to taking over that small market. I'm an enthusiastic hobbyist photographer, and switched to mirrorless in 2014 (Fuji X-T1). I knew immediately after getting my first mirrorless camera that I would never buy another DSLR.