There's no difference really. Not all strategy can be converted to a trading bot anyway so you can only trade manually. If some or all of the parts of the trading system can be converted to an automated process, then of course, it's way better because it will lessen the stress and effort on your end. I don't see the point of choosing one over the other.
People who strictly choose manual trading only thinks that they have the control but unfortunately, there's too much uncertain parts with the financial markets. If some things will help you control some parts of the trading process, that will always be the best path.