At least in regards to the later point about the price of a camera. I think my old camera was about $3,000 with the lenses (7D mk ii). I had it for 5 years. In that time, I’ve bought 4 phones. The cheapest of which was $700, and the avg price which was $1000.

The kit is about $1500 on eBay these days. The body went from $1600 (new) to $700.

Lens technology is slow moving - at least for the middle prosumer market, and lenses keep their value. You can also upgrade the body and glass independently.

For a while, I thought we might get swappable sensors, but with IBIS and smarter chips that seems less likely.

These cameras retain their value pretty well, and thus so far, the camera tech in phones hasn’t turned into a race.