As The Merge even on Ethereum is fast approaching a lot of people to become curious about what will happen therefore a lot of misconceptions are being created along the way.
As we all know the major problem with Ethereum right now is the high transaction fees.
So for me the common misconception of The Merge event for Ethereum is
"The Merge will reduce gas fees." or "Transactions will be noticeably faster after The Merge."
What else misconceptions you often hear or read?
You can read more here:
https://ethereum.org/en/upgrades/merge/#misconceptions