how is grapevine at all similar to discord? discord doesn't have a social feed, was aimed at the gaming community, you can have your own channel, grapevine doesn't support private servers, group audio/video calls, looks more like a semi-professional network targeted at the working audience.
Grapevine and Discord both having topic or interested based groups. All sorts of communications happen on Discord not only gaming. Agree on the part voice and video
"topic or interest based groups" - yes but dc has customized servers and no social feed as such, current gv model is more similar to reddit than dc
"all sorts of communication happens on dc" - yes but dc was initially meant for the gaming audience it is now that it's being widely used for all kinds of communities
also you have the concept of server boosting and other server perks in dc unlike gv
Grapevine is more similar to reddit. It can be considered a subset of reddit ig. Discord is similar to reddit with the addition of voice and video calling features.