Apparently there's 500 hours of video uploaded to YouTube every minute (30 seconds every millisecond). Assuming 4K@60fps, that works out to 14,929,920,000 pixels per millisecond.
If YouTube wanted to give every incoming pixel its own UUIDv7, they'd see a collision rate just under 0.6%.
> Assuming 4K@60fps [...] they'd see a collision rate just under 0.6%
This doesn't detract from your point of collisions like that being viable at that scale, but assuming an average of 4K@60fps is assuming a lot. The average video upload there is probably south of 1080p@30fps.
You're glossing over the fact that they assumed youtube would want to assign a UUID to each pixel in a 4k@60fps video as the use case that this would fail for...
If YouTube wanted to give every incoming pixel its own UUIDv7, they'd see a collision rate just under 0.6%.