If the event planner is a single centralized global entity, then the end-user features are less significant, that is correct - well aside from no one being able to take down the data and it being open source. If you are talking about everyone hosting their own, then this is incorrect - even if you think they could be federated "discovery" of new groups and members is practically impossible when a new server is added. There is a significant advantage of having a global registry, when it comes to discovery.
Get Feedback, early and continuously. By people you trust and am comfortable telling you to do things.
Learning to code easily leads you down a rabbit hole where you can't see the outside anymore. Getting feedback allows you to see beyond what you do at the moment and also realise when to do the next step or move to a different topic.