Who is helium Blockchain competitor?

Who exactly are the primary competitors to Helium's Blockchain technology? Could you elaborate on their key strengths and weaknesses compared to Helium? Additionally, how does Helium differentiate itself from these competitors in terms of scalability, security, and adoption? Furthermore, what are the potential challenges Helium faces in maintaining its competitive edge in the rapidly evolving blockchain landscape? I'm interested in understanding the overall competitive dynamics within this space.