I tried this approach and the latency was through the roof, easily a second or so off, making it effectively useless for video conferencing. Switched to an HDMI grabber so I could get something that was actually realtime.
You need to dial in the fps. It's a little bit of work to try different parameters and might not work for every camera. But with most cameras I was able to get the latency below 300ms which should work for most use cases.
Not sure this would work with every camera. My particular model does not support remote shooting over USB. Newer models of the same camera do and Sony even provides software to go the USB route.
The native Sony software will only support 720p resolution. So gphoto2 still offers better resolution.
"Shooting over USB" is not a requirement to use this. The camera only needs to be able to output the preview stream via USB, which works with most cameras.