Polygon basically checkpoints a spreadsheet onto the eth chain on an interval, but there is no way to guarantee that there weren't any shenanigans between the c

Polygon basically checkpoints a spreadsheet onto the eth chain on an interval, but there is no way to guarantee that there weren't any shenanigans between the checkpoints. This is a big improvement over say BSC which does no such thing, but it isn't the security of a true eth L2. Real L2's can prove that their output to L1 is legitimate either through zero knowledge cryptographic proofs (loopring, zksync) or through a game theory fraud check (optimism, arbitrum).