Why do you want to know another platform to compete with Ethereum? Actually, you don't need to ask this, just monitor the development of several platforms that potentially become the competitors of Ethereum. For example, you can take a look at Binance smart chain, Tron chain, or Polygon chain. These chains can be the strong competitors of Ethereum in the future. Just monitor them, then you can conclude how far they can be great competitors of Ethereum now.
Polygon is not a competitor to ETH but they are just aiding the ETH network to scale. There are plenty of competitors for them especially BSC and even if ETH regains their old power, i am not sure how many projects will be using the ETH network as there are plenty of options available right now, but the developers have plenty of options to choose from right now.