What is the purpose of declaring an extra local variable in this OpenZeppelin ERC20 implementation?

From the implementation of ERC20 from Openzeppelin using solidity ^0.8.0, the _transfer function is like this:

function _transfer(address sender, address recipient, uint256 amount) internal virtual {
        require(sender != address(0), "ERC20: transfer from the zero address");
        require(recipient != address(0), "ERC20: transfer to the zero address");

        _beforeTokenTransfer(sender, recipient, amount);

        uint256 senderBalance = _balances[sender];
        require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
        _balances[sender] = senderBalance - amount;
        _balances[recipient] += amount;

        emit Transfer(sender, recipient, amount);
    }

Is there a special purpose of writing

uint256 senderBalance = _balances[sender];
require(senderBalance >= amount, "ERC20: transfer amount exceeds balance");
_balances[sender] = senderBalance - amount;

instead of simply

require(_balances[sender]>= amount, "ERC20: transfer amount exceeds balance");
_balances[sender] -= amount;

?