"Cameras all use H.265", curious , what cameras are you referring to?

While some cameras do support it, it's much more common to use ProRes, DNxHD/DNxHR or h264 in all-intra mode (as e.g. in XAVC-I and XAVC-S-I).

h265, or long-GOP codecs in general, are only really used for long talking head shots or lectures.