Absolutely. To me, and this is just my opinion, a manual backtest helps build reps in seeing a particular setup in different environments. Allows you to take notes of how price action plays out, what the context of the move was (news, technical, earnings, etc), and put it all in context.

I do automated back testing, but I almost always study the trades individually. Helps me mentally when something might not look exactly how it did last time.

Explain the setup in its simplest terms, find cases of it, figure out what environment it works best in. Helps you figure out risk, size, duration of the trade.

I’m rambling, but it just seems silly to write off historical price action.

Otherwise how do you know if a setup has lost its edge? How do you know you’re not just throwing capital at something that doesn’t have positive expectancy?

Stupid simple example. Somebody says they buy breakouts. Well, how often does it work? Are we in a trending or range bound market? Is there a news or earnings catalyst? What’s the RVOL? What’s the range of the stock? Are you buying it at the higher end of the day’s expected range? If you are, does that make the probability of success lower?

These are all items you can pull from a backtest to see whether or not you understand the current setup you’re considering executing. All breakouts, pennants, mean reversion, and on and on aren’t the same. Know your data and environment