A big one that hits small sites I think is simply tech staff with the ability to properly encode HTML video. You lose them as soon as you say vp9, h264, or av1.
This is true, but I would also suggest that small sites would like be better off simply doing a single H.264 file, which is what comes natively off of many cameras and is an export preset in almost everything. If you're not publishing long high-res videos for many thousands of people, you're almost certainly going to be paying more in staff time than you see from the bandwidth savings.
But it's not only about bandwidth. An h.264 video file off a camera is rarely going to be a good choice to throw up on the web.
Cameras write files with extremely short GOPs and overly high bitrates because they have to capture live video and can't know what the next second of content will look like. They need to use settings such that pretty much anything captured by the lens will be captured in good quality.
An offline encoded h.264 video can have far more processing thrown at it. Typically you'll see longer GOPs and a much tighter tuning of bitrates and more features like b-frames and CABAC encoding enabled.
A file directly off a camera can have bitrates of several tens of megabits a second. Even short videos are huge and won't stream well to many. A lot of devices also have limits on the profiles of video they'll even decode.
Someone throwing a camera's direct output onto YouTube can be guaranteed better than 99% of all devices on the Internet can be served a watchable version of the content.
A big one that hits small sites I think is simply tech staff with the ability to properly encode HTML video. You lose them as soon as you say vp9, h264, or av1.