Onion over vpn doesnt make sense to me

i use nordvpn, and they offer onion over vpn. im somewhat confused as to the benefit of this. based on this graphic they posted on their site…


the connection between the vpn server and the tor network is not encrypted. so if someone is snooping on the vpn server, its basically like the tor network isnt there. how is this any different than just connecting to the vpn server alone? in both cases the connection leaving the vpn server is not encrypted.
am i missing something?