As others have mentioned, you can't beat physics - a larger sensor will always capture more detail, in addition to being able to provide true bokeh effects.
However, there are certain advantages to the iPhone cameras, with the biggest one for me being handling multiple exposures and post-processing especially for outdoor portraits; I personally find it a pain in the ass to try to get the sky from overexposing and having to dodge shadows in people's faces when post-processing outdoor portaits.
Also, as others have said, it depends on where you're viewing the photos. It's going to be difficult to see many differences between a DSLR pic and a phone pic on a phone screen, but show those pics on a larger display like a monitor (or even print them out) and the difference becomes very obvious.
Personally, ever since the iPhone 8, phone photography has replaced 90% of my photography. I still use my mirrorless camera for planned portraits, special events, and outdoors vacations, but not having to carry my mirrorless camera most of the time is a great feeling when aiming for "good enough" everyday pictures.