Your choice of camera can also affects performance a lot due to format. Some formats are very slow to edit and requires ingestion and re-encoding for decent editing performance.
I do everything in a mix of h.264 and h.265
Why would you export anything in h.264 today? Or do you mean your device actually natively records to h.265?
The devices. I try to use h.265 whenever I get the choice.
This is not a good choice. You want to edit in a format that is easy to decode and H.265 is not. So to be able to edit you either have to re-encode your H.265 video clips into another format (aka transcoding) suitable for your editor or suffer much slower editing performance.
If you shoot in H264 you can probably edit it directly without much impact. The editing software will re-encode it on the fly.
H.265 is a delivery format.
GoPro says h264 only for legacy older devices. H265 is their editing format.
H265 works fine on newer hardware.