It’s not because phones can’t do that, either; Samsung, Huawei, Apple, and others are all able to cram 4K60 in their smartphone cameras, but Google decided against it.
So what’s the reason? Google says that the biggest factors were the focus on doing 1080p recording right, and storage size. According to Google, most people still record in 1080p, not 4K, so that’s where they wanted to do the most work on the Pixel 4. It makes sense, too, since 4K, especially at 60fps, does chew up a ton of storage on a phone.
But some of that is just Google’s fault. They nixed the unlimited original quality backup on the Pixel 4 for photos, and the phone only comes with 64GB of storage. You can opt for the 128GB model, but it feels like Google is just pushing their cloud storage services to hold your high-resolution videos. And that’s still a pretty flimsy excuse, considering Apple also uses 64GB of storage as their base model, and they push paid services harder than anyone, but you can still do 4K60 on a 2019 iPhone.