Take a look at all of the blocks coming in https://polygonscan.com/blocks
Every block is pretty much 100% full. Now click in on one of the blocks, and look at the transactions, for example: Polygon Transactions Information | PolygonScan
Now see that almost every transaction is a send to self transaction. Now click into one of those transactions and you see that they are sending themselves 0 matic, and just paying gas, like this Polygon Transaction Hash (Txhash) Details | PolygonScan
These are not interacting with any contracts or doing anything like that. This is a DoS attack on the chain. It has been ongoing for a while now.