For the same Layer 2 network, why did fees drop so much after the Cancun upgrade?
Blob data cannot be read by the EVM. Contracts only receive a versioned hash calculated from the blob’s KZG commitment.
Key point: When comparing Layer 2 fees, distinguish between the Layer 2 network’s own execution fees and the cost of submitting data to the mainnet. Both can change.
When a Layer 2 network writes blob data to the mainnet, the blob fee is also settled using $ETH .
It’s best to invest only money you can afford to lose without affecting your life.

This is just an opinion shared for discussion. You assume all risks.