It would be helpful if the ideas are clustered. Only non-focused founders will spend their time on reading all ideas, which is needed to find matches in special

It would be helpful if the ideas are clustered. Only non-focused founders will spend their time on reading all ideas, which is needed to find matches in specialized areas. YC could offer hierarchical subreddits for business sectors. It would be possible to collaborate with founders who are attracted to the same topic and it would be possible to offer opportunities to people who want to work in the broader area.