Polygon is part of the Ethereum ecosystem and leverages its Ethereum network effect, while the above projects are competing ecosystems built from scratch.
Polygon natively supports any scaling or infrastructure solution from the Ethereum ecosystem.
Polygon Network is a modular, Layer 2 Security-As-a-Service platform. It enables the creation of Ethereum-compatible blockchain networks that can interoperate with each other. This helps solve the main problems of Ethereum, such as network congestion, low throughput, and high gas costs, which create limitations for blockchain developers and hinder the development of the ecosystem, and therefore, widespread adoption by people.