One big advantage of using a popular VPN is shared endpoints. Your traffic is mixed in with hundreds of thousands (if not millions) of other users.
Using your own VPS means you are easier targeted, tracked (on layer 3) and located -- since your VPS likely has a dedicated IP and you probably have a non-anonymized account with the provider. You're still relying on your VPS provider to not monitor outbound connections as you are on the VPN provider.
Using your own VPS means you are easier targeted, tracked (on layer 3) and located -- since your VPS likely has a dedicated IP and you probably have a non-anonymized account with the provider. You're still relying on your VPS provider to not monitor outbound connections as you are on the VPN provider.