I hope this cross-post will not be frowned upon by the respected community, as I believe the linked article helps eliminate certain widespread misconceptions about the differences between Cyphal and DroneCAN. Behold the article:
tl;dr: Cyphal is similar to DDS, DroneCAN is similar to I2C. The article argues that modern unmanned vehicles would benefit from the adoption of Cyphal as it enables more advanced and robust network architectures.
It helps to know that Cyphal is already supported in the PX4 Autopilot (also there’s a PR to ArduPilot).