Yea, but you have USB3 high speed, record pro-res directly onto, external storage.

So you can spend $100 on a 1TB external drive (rather than $100 on another 128gb of internal storage) and you're way better off. If you're use case is 4k60 ProRes, this makes WAY more sense than recording locally.

Hopefully they don't block full resolution ProRes recording like they did on the 13 series. The 128GB version of the 13 and iirc the 14 was only able to record 1080p60 ProRes, regardless of available space

I'd imagine most people offload them to iCloud, and don't keep copies on the iPhone. At least that's what I do.