https://www.chainbits.com/news/harmony-one-vs-polygon-matic/Quoted from the article:
"Once we compare both of these protocols, it is evident that both have a higher value proposition to the Ethereum and blockchain community as a whole. However, Harmony edges Polygon out in the regard that it is actually an entire blockchain onto itself while also providing a bridge that enables interoperability with Ethereum and other blockchains such as Binance Smart Chain. Thus, Harmony is in direct competition with layer 1 blockchains like Avalanche, Solana, and BSC, as well as layer 2 solutions like Polygon, Optimism and Zksync. In contrast, Polygon is just a level 2 scaling platform that uses ETH for security and provides efficiency and speed for transactions.
The fact that Harmony has over 1,000 validators responsible for the staking activities on the blockchain as compared to 110 validators for Polygon, makes Harmony more decentralised with a larger dissipation of governance responsibilities in the network. Thereby limiting chances of one sided takeovers and attacks on the network. Harmony also remains to be the network that in theory has a much higher TPS than Polygon which enables faster transactions and improves network efficiency.
Considering all the aforementioned aspects, it is evident that at this moment, Harmony brings a higher value proposition for it’s users for a more long lasting solution to Ethereum’s issues."
Also, look at the table in the article and compare yourself.
Another well written review:
https://medium.com/coinmonks/harmony-one-update-my-take-on-its-potential-b17cfbb230a8