They are similar in some areas, such as that they both have something called so-called rollups (aka ,“zero-knowledge rollups “, which are used to validate data on a blockchain in a way that is faster than the more standard proof of game mechanism). But Loopring focuses more on helping decentralized exchanges (along with a rumored partnership with an NFT market), while Polygon allows people to make smart contracts, give loans, while also having the capability for decentralized exchanges.But although Polygon has more use cases, this does not mean that the technology is not going to be.
At the time of writing, Polygon is the 16thste most popular currency by market capitalization, while Loopring is 75ste. This makes the latter way more volatile, which can create greater rewards but is more risky. Plus, given their competitors, it’s fair to say Polygon is much more popular right now. It’s like Everton against Mansfield Town.