Demand is way down because while a $5000 lens on a nice camera is better than my phone lens, my phone is close enough for most purposes. Also my phone is free, in the days of film a single roll of film by the time you developed it costs significant money (I remember as a kid getting a camera for my birthday and then my parents wouldn't get me film for it - on hindsight I suspect every roll of film cost my dad half an hour of work and he was a well paid software developer). This cost meant that you couldn't afford to practice taking pictures, every single one had to be perfect. So if you wanted a nice picture of the family it was best to pay a professional who because of experience and equipment was likely to take a much better one than you could (and if something went wrong they would retake for free).