Why bytes.concat() over abi.encode?

[RamanSB]

foundry-merkle-airdrop-cu/src/MerkleAirdrop.sol

Line 70 in b4c627c

bytes32 leaf = keccak256(bytes.concat(keccak256(abi.encode(account, amount))));

I noticed the following code for generating a Merkle leaf:
bytes32 leaf = keccak256(bytes.concat(keccak256(abi.encode(account, amount))));
The goal is to perform a double hash to prevent second pre-image attacks. However, bytes.concat seems unnecessary for a single bytes32 value.

I would've suggested using abi.encode.

bytes32 leaf = keccak256(abi.encode(keccak256(abi.encode(account, amount))));

I appreciate that bytes.concat() accepts a bytesX (x is an integer <= 32) and returns bytes memory which is what we want to pass to our keccak256 to get the 2nd hash, but abi.encode also does the same thing which seems a lot more straightforward?

Chisel