https://wccftech.com/heres-why-pixel-4-4-xl-dont-record-4k60-video/

Just about every flagship released in 2019 came with support for recording 4K video at 60 FPS. The Google Pixel 4 series, however, was not one of them. In a statement earlier, Google explained why they opted to limit the frame rate to 30 FPS. The company argued that most users use the default 1080p 60 FPS so they focused their energy on improving his mode. It was reportedly pulled at the last minute after having been a part of the original release. Today, we stumbled upon the real reason why Google didn't include the option on the Google Pixel 4.

So, about 4K60 on the Pixel 4: the limited storage may not be the only reason why it isn't supported. Thread: