The shallow depth of field portrait look generally appeals to people, but of course it's subjective. It literally puts the focus on the subject, and de-emphasizes the background by blurring it. There are also many great portraits taken by famous photographers where everything is in focus. Keeping everything in focus can be especially important when you are trying to show a subject in their environment. In those situations many photographers will shoot a bit wider while stopping down to an f-stop that will keep the entire scene in focus. Most of the time people shoot what I would refer to as candid portraits. These are not professional portraits taken in a studio or in a controlled environment using professional portrait lights. These are spontaneous snapshots of a person where the environment may not be as important. in fact we may want to blur that background as much as we can because it might be full of distracting elements like other people, dirty dishes, etc.
On my larger sensor DSLR and m4/3 cameras I frequently shoot with shallow depth of field because I simply need to shoot with a wide aperture in a low-light situation. In those cases a blurred background just happens because of the wide aperture. If the background is important to me, I may increase ISO or use flash so I can use a smaller aperture to bring everything into focus.
Among professional portrait photographers the shallow depth of field look kind of goes through trendy phases like many other techniques, and right now you could say it's very trendy among the general public because smartphones are now capable of achieving the shallow depth of field look by blending data from two different images taken with two different cameras (on smartphones with dual lens). Quite often the effect looks very authentic (as if it were created optically rather than using software), and other times it can look like really bad Photoshop. From the samples I've seen, it looks like Apple's technique is more realistic looking than most. I have been playing with it quite a bit on the iPhone X and so far the results have been good. Since I take a lot of candid photos of my kids, it's nice to have background clutter blurred out in some situations. In other situations I might want the background. If you are trying to capture something quickly, the regular Photo mode is faster and more reliable. If you have time to experiment, why not experiment?
Portrait lighting is beta, but if you have the time why not experiment with different looks by selecting Studio lighting, contour lighting, etc.? In my experience the Stage Lighting is the one that feels most beta. It doesn't always mask the subject as cleanly as it should and ends up looking like bad Photoshop. I'm sure it will get there with future updates though. Rather than thinking of these effects as gimmicks, I would just think of them as photographic tools that are worth exploring so you understand when they might improve the final photo.