Video conferencing worked perfectly when it was still done over circuit-switched digital telco networks. It’s only the Internet that has botched things up.
If by "botched things up" you mean "Made affordable." Nobody other than Vint Cerf will argue that circuit-switched networks are not superior from a QoS point of view, but they can be orders of magnitude more expensive to build and maintain.
They should be feasible to implement within a building, between buildings on the same street, and probably between geographically diverse sites of multi billion dollar companies that spend 30%+ of their labor hours on site-spanning meetings.