Why do people often say “wait for 6 confirmations” for Bitcoin, but “finality” for Ethereum?
This is how I understand it: Ethereum requires two-thirds of staked ETH to participate in voting for finality. If too many validators go offline, finality pauses, but blocks continue to be produced as usual.
Finality is the property that confirmed transactions or blocks cannot be reversed or rewritten.
My current rule of thumb: when depositing or withdrawing between different chains, finality times vary from chain to chain, so a slow arrival doesn’t necessarily mean something has gone wrong.
On Ethereum, the $ETH staked ETH is the guarantee of finality: overturning a finalized block would result in the loss of a large amount of stake.