Yeah that’s bullshit.

Hand Joe Sixpack a high-end DSLR (or MILC, since it’s 2023) and an iPhone and I’ll bet you he’ll take better pictures with the iPhone.

What dedicated cameras do is give you more options; you can change lenses, add filters, change exposure, etc. You have much more creative control. Sure, you also get better optics but that doesn’t matter much in the hands of an amateur.

Phones do a shitload of processing on the captured images. A DSLR does little to nothing. You are expected to do that yourself on your computer afterwards (again, more creative control where the phone makes those decisions for you).

The automated processing on phones does an excellent job for the kind of snapshots an average user wants to make. Much better than what they would be able to do themselves.

If you know what you’re doing you can do amazing things with a DSLR/MILC but in the hands of the general public the phone will give much better results 100% of the time.

A good camera doesn’t make great pictures, a good photographer does. Don’t buy an expensive camera thinking your pictures will suddenly look amazing. They will look much worse than the pictures your phone makes until you learn how to properly use it and how to process those images.