Both Intel and Realtek 2.5GbE LAN ports on mid-high range motherboards (such as the x670e PG Lightning and Z690M Aorus Elite) have jittering issues exclusive to VRChat.
The jittering is not visible locally, however to every remote player there is extreme jittering and lack of stability when moving quickly.
Rejoining the instance temporarily fixed this for only 10-30 minutes before occuring again.
Setting the 2.5GbE NIC to run at 1GbE does not solve this issue.
Does not occur via Wi-Fi or native 1GbE NICs.