What is the point of passing the traffic through multiple VPN servers? It makes sense with Tor because it is decentralized, but with VPN all servers are controlled by the single entity. Does multihop with VPN provide any privacy or security benefits or is it just a marketing gimmick?
It slightly improves your privacy/security.
Your ISP isn’t able to learn your VPN IP address, which means your local law enforcement can’t get it without international cooperation. It’s typically harder to get this type of information internationally, but it depends on the nature of the request.
Oversimplified, it might help you if you committed a misdemeanor, but it probably doesn’t matter if you are want for a felony.
Multihop only makes sense if you are hopping to and from ideologically opposing countries which you would know wouldn’t cooperate easily with one another. The problem is you can be sure that connections from those two points would presumably be monitored and surveilled as much.
This explanation by Mullvad is pretty comprehensive, giving you a good idea how multihop works and what its benefits are as well as if you want to enable it or not.