This very much "depends".

Many algo strategies are indeed programmatically simple (e.g. use some sort of moving average), but the parametrization and how it's used is the secret sauce and you don't want that information to leak. They might be tuned to exploit a certain market behavior, and you want to keep this secret since other people targeting this same behavior will make your edge go away. The edge can be something purely statistical or it can be a specific timing window that you found, etc.

It's a bit like saying that a Formula 1 engine is not that far from what you'd find in a textbook. While it's true that it shares a lot of properties with a generic ICE, the edge comes from a lot of proprietary research that teams treat as secret and definitely don't want competitors to find out.