If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.
Yeah, it depends on the specific thing you want to do. Sometimes one person is enough for the whole project. Sometimes one person is enough for making the most simple version of the project; and if others are impressed and joined, they can make the project greater, but their participation is optional. But sometimes you need a team to create even the smallest version of the project (either because the project is too large in scope, or because it requires many different specializations).
Not being able to cooperate limits a person to one-person projects; and only those where they have all the necessary skills.