Perhaps the M.2 HAT+ and a decent SSD?

USB3 could plausibly be faster than the SD card as the spec allows for 5Gbps+ but I don't know about Pis that much, I'd defer to someone with experience.

As a photographer I can tell you that SD cards, even high class ones have laughably awful speeds - any proper camera that needs to do video will use CFexpress Type B cards which are tremendously faster.

> Perhaps the M.2 HAT+ and a decent SSD?

That won't help OPs Pi4, the PCIe interface is new on the Pi5. USB is the best you can do on the older ones.

Proper cameras use film ;)

Seriously though, there are plenty of top-end cameras that use SD cards (all Nikons, for example).

EDIT: completely missed that you said video, ignore me!