Does the Fear & Greed Index actually work as a strategy?

Has anyone here actually used the Fear & Greed Index as part of their strategy? For example, buying when it drops below 20 (or even 10), and then taking partial profits when it gets around 70. Looking at the history, it seems like markets mostly recover after the index drops below 20, but sometimes it keeps falling further to extreme levels like 3–5 before recovering. On paper it sounds like a simple way to buy fear and sell greed, but does it actually hold up in real market conditions? Or is it too simplistic to rely on a single sentiment indicator? Curious to hear if anyone has back tested this or used it consistently.