I personally don't see the appeal of using an iPhone for film making. I don't want to tie up my phone and communications device on set as the production tool. An iPhone costs now as much as a Blackmagic Design Pocket 4k camera. Sure that may not include lenses but there are a ton of good budget level lenses out there now.
The way Apple sells these phones and limits the cool new video features to the latest model one would need to upgrade their phone every year which costs a lot. Just to match many of the capabilities of existing video cameras. It may seem like its a free video camera you get with the phone but you are paying for that camera and three lenses and three sensors. Lets say over the past three years one bought a Pro iPhone to shoot video first for the better computational low light, then for the cinematic mode and now for the cinematic mode in 4k. Thats $3,300 in three years vs a camera that can already do all of that that will last many more years. You can get a P4k for $1,300 and the other $2,000 will buy a lot of lenses, audio, lights and support gear. all of which will yield 1000x better movies than just shooting with the iPhones.
Apple promotes film making on the iPhone with a high production value crew because thats the only time video looks good from an iPhone. Unless one has the budget for a full crew and equipment the iPhone is nowhere near a production ready camera.
Don't get me wrong. Its neat what it can do and for those that wanted a new iPhone anyway its cool to have a video camera this good in their pocket. But no professional is going to rush out and buy an iPhone for a serious production. They may utilize sometimes as a tool to accompany other cameras on a production but nobody is going to plan a budget production around just using an iPhone. Not unless they were hired by Apple to do so for marketing and promo reasons.
When Apple figures out a way to add/remove storage at will, add/remove batteries at will and control aperture or some sort of chemical or electronic ND to adjust exposure then and only then will pros consider using an iPhone for serious work. Using just the shutter speed to adjust exposure outdoors is the absolute opposite of professional video.
i have BMPCC6k and iPhone 13 Pro. The BMPCC just isn't convenient enough sometimes. Autofocus barely works on many lens, the battery barely lasts 15 minutes, to get 1TB of storage, you'd need to attach a usb-c SSD somewhere (or let it dangle), no stablization in the camera, and so on. when you need to get job done fast, iPhone is the way to go.
with a moment lens, you can get a cheap anamorphic setup. and since it doubles as your phone, you're not paying $1k EXTRA. it's the phone you're going to get whether or not you're making movies. so maybe you pay an EXTRA $500 for the 1TB premium.
steven soderbergh shot 2 movies using an iPhone and he's a professional.