Right now this kind of thing is generally a leadership-driven project. While it's easy to make a space if you have a venue, someone also has to stand up and say

Right now this kind of thing is generally a leadership-driven project. While it's easy to make a space if you have a venue, someone also has to stand up and say "This space is for this purpose and I am going to work on advertising it as that, and organizing it so that it gets people who are interested in this topic in the door and talking to each other and doing valuable things with their time." And then the technical problem is reduced to how cheaply and effectively they can message people about group activities, with physical presence being expensive/effective and comment threads being cheap/ineffective, and other tools like email, TV advertisement, etc. going somewhere in between. It takes a LOT of time and energy when you're going all-out to build up contact lists and follower counts and push messages out to them and make arrangements and do deals. This is how we now do present-day entrepreneurship; there are companies that go without physical presence, but we like having it around. If you can solve this in a way that makes it an order of magnitude easier to organize activity, it would be a huge breakthrough for society, because it's the cost of communicating these basic "allocation problems" that ultimately drives the economy into monetized territory.