1) The best camera is the one you have in your hand... Or in your pocket. Your fancy Sony or whatever doesn't help if it's at home or turned off in your bag with no lens on it when something magical starts happening that you wish to capture.
2) Most people don't care. They're not photographers. All they want is to take a picture, have it look "good enough" with zero effort, and be able to immediately share it with friends. You're taking about an entirely different market.
Not necessarily. Sometimes it's better to forget about taking the shot if all you have is a phone camera.
The best camera is ... the one that's best tailored for the shot. Everything else is a compromise or, as we used to say, a waste of film.
They'll pull their Pixel out of their pocket, hit the power button twice, and immediately take 100 photos that will all end up looking at least halfway decent.
I carefully plan my art. I know where the sun will be. I know where I'll be standing, with what cameras, and what lenses on them. I'll have the manual settings already configured. I'll even have in my head what frame the final picture will go into.
But if my daughter suddenly starts running through my leaf pile with a huge grin? In pulling out my Pixel.