I think this is another version of the old Wall Street adage, "Don't fight the ticker."

Having said that, I think that it really matters where you are in your investing career. If you're in your 20s-40s, it makes sense to stay in the market (assuming you have the emotional resilience to not panic sell when the market crashes).

If you're in your late 50s or later, it makes sense to be somewhat more cautious, since you have far less time to let your portfolio recover before you need to start drawing it down.

Here's my personal take on things: https://opher-ganel.medium.com/my-investments-lagged-in-2021-3-reasons-im-still-happy-192ff2f111d6