In a hybrid/remote culture, how many meetings in your organization have a video-on mandate, where team members "must" switch video on in order to cultivate face to face collaboration?

I don't think we have any that are mandated, and different teams had (during pandemic) and continue to have a range of preferences around cameras being on. I always have mine on, and if it's my meeting, presentation, learning session, etc, I will ask participants to turn it on if they're able to. 

I always ask my team to switch it ON. Because in remote situations those visual cues will give us a lot of details likes interested, excitement, attentiveness, etc.

While I enjoy the face to face conversations, what is the justification to see someone's face?  Just to improve interpersonal communications?  I don't think virtual views of your colleagues will satisfy that goal.  Globally, you will find some cultures where participants do not want to share a video of themself.  I have experienced face time with colleagues using Zoom and Skype, and didn't see where videos made up for the interpersonal communication that is commonly missing as compared to in-person meetings.
One exception to this concept is my experience sitting in front of a 36 inch monitor about 18 inches away from me doing face to face talks with one or two other people on the other side of the monitor who also had the same monitor and desk.  There was no lag time and lighting was great.  So, I agree in concept with the desire to video but I don't think we are there technologically yet to benefit from body language, tone, etc.

Interesting question. I've already worked for 1 year in a company where some of my colleagues I've NEVER seen the face of. I find that kind of inelegant, I don't know.

We have no video-on mandate at all, but nearly in all meetings the colleagues have their video on by themselves. Only in meeting with many participants, there is a larger portion of participants with video off.