We could be stuck on a concept for hours before someone has a solution to share. A community to learn with allows you to connect with others, network, share resources and knowledge. We learn from others by seeing how they solve problems and getting feedback on our own work. People also get encouragement and motivation from the community to keep learning. When you are learning as a group, you are going to be exposed to lots of different ways of solving problems. There is value in seeing different solutions to the same problem. You may be able to do things one way but when you see how others have solved the same problem, you can learn new ways to approach things that you may not have seen before.
With a community you can have a buddy system that works together, helps each other out, answers questions, gives advice and feedback. If you are a new student you are likely to be connected with someone who is more advanced. This student will show you the ropes and introduce you to other students.
If you have a question, you are much more likely to ask someone who has just learned that very thing than you are a teacher who has been doing it for years. Experienced students may also get a leadership role and lead a group of new students. The more you know the more you are able to help others.
If you are learning in a community you are also more likely to follow through and stay on track. You are accountable for the work you are doing. Having regular check-ins and projects due helps students stick with the coursework even when it gets difficult.