Bigger lenses capture more light and produce better quality video, especially in low light.

Good point. But the iPhone camera proves that you can get away with bad lighting conditions using post-processing. I think you can still make professional-looking video using just an iPhone.

If by videofile you mean professional, then sure, but if you mean chasing quality that exceeds human perception limits, then no, if anything, the lenses are likely a compromise in order to get them so close together.

iPhone video is impressive, but even moderately successful YouTube channels upgrade once they start making money. Some even use big cinema style cameras like red 8k cameras.

Making quality 10% better doesn’t necessarily mean the device is 10% bigger. The device could be 10x bigger for a boost of 10% in definition. Law of diminishing returns.

Yes, that's exactly what I was thinking. But also, good enough is good enough.

We're getting into "videophile" territories here.

You would kind of expect that from a company that makes professional video equipment.