[bsder]

Larger packets and bandwidths.

Bandwidth: you can't ship backup camera video or entertainment system audio over CAN, for example.

CAN was meant for short, real-time packets. 8 bytes in initial configuration. CAN FD allows 64 byte packets.

You spend a LOT of protocol doing packet fragmentation and assembly using CAN--which then negates a lot of the real-time guarantees.

CAN should be used for the short safety critical stuff. Ethernet should be used for everything else.

[elcritch]

Ethernet can handle real time now even in bus configurations!

10BASE-T1S is a new standard geared for automotive. It uses physical layer collision avoidance instead of classic Ethernet exponential backoff. This provides deterministic maximum latency.

Though you can get max latency guarantees with switched Ethernet and the appropriate switch QoS and hardware.