Yes, I have a phone with me, and it's great for when I forgot my camera, but there is no comparison in the freedom that the 5D gives me in postprocessing compared to a phone sensor. Phones are great for 100% of the things the average user wants, but not enough for what many artists want.
[0] It's not technically impossible, but it's a huge hassle and probably won't be near as good as with cameras.
It doesn't matter to the people who would previously have paid for a product. That's the point being made.
Technical excellence will always matter to some, but the point the GP is making is that the quality of smartphones has reached a level where a larger and larger segment of 'people who would have paid' now rest within the smartphone circle on the Venn diagram.
If the OP is talking about the general public's perception, with most of them not being photography enthusiasts, I tend to think this rings true.
If you're a photography enthusiast, then yeah, not true at all.
The number of people who want a camera is vanishingly small. What almost everybody wants is a thing that takes pictures. These days, that doesn't have to be an extra thing; they're going to be carrying their phones for all sorts of other reasons. (BTW, lighting is far, far more important than the gear you use to capture the effects of the lighting. If I had to tell people to pay attention to only one thing, it would be the lighting - whether that's "found" lighting or something you deliberately set out to create. Get that right, and "fix it in post" becomes a whole lot less attractive.)
I have been wonder at what point will Phones camera reached the law of diminishing return? I thought the iPhone 11 with night mode finally closed the gap for most consumers, we have a roadmap for another 5 years of Lens, Optical Zoom, and Sensors with better light sensitivity.
Apple likes to hype up features, but they still haven't come out and claim they have a DSLR like Camera system. I wonder when they will do that.
No, it depends on what you want to do. If you want to do street photography, for example, even as a novice, you're going to have a much easier time using a longer lens so you don't get near your subjects and ruin your shots by drawing attention.
There are narrow lenses for phones as well.
Have you looked at real "portrait mode" photos? They only really resemble narrow depth of field at thumbnail sizes, but as soon as you open them fullscreen, all of the mistakes jump out and make it look like a terrible Photoshop job. I'm sure it will get better, but I certainly wouldn't say it's anywhere near the last straw yet.
Photographer here. Cell phones have become very capable cameras. I've seen whole segments of my client list evaporate with the last generation of camera phones. The last straw was when the iPhone got portrait mode and could render bokeh/blur like lens physics.
Two things though...
1. The phone cameras are really really good. In the right hands, professionally capable in many situations. You don't need to know the basics of photography/physics to operate a camera phone properly. It helps, but the average person can just point and shoot with solid results.
2. We mostly just publish to social media now. The need for extremely detailed, high quality media work is diminishing at the bottom line. The market is changing. The quality in which we document is shifting. 8K is a buzz word, not an archival format for future proofing.
There isn't a cell phone in the world that could even touch the capabilities of a high end DSLR or Mirrorless camera, but that simply just doesn't matter now.