As the saying goes- generally speaking; time in the market beats timing the market.
A lot of people got burned, especially during early COVID days when the growth funds and stocks were tanking hard. I personally know a few people that moved to conservative too late, and then didn't move to growth quick enough. Had they just stayed in the funds they were in, they would have been perfectly fine and actually considerably better off.
Unless you really know what you're doing, I would be very surprised if you found anyone who suggested it a good idea beyond just luck.
Agree, I should have left it put, but I tend to back myself and usually come out better off for it. For example 5 years ago or so I had a mortgage at 8% or fixed for 4 more years. I could see rates were falling so I paid a minimal break fee to go onto floating rate, cost me a bit more for a couple of months but rates kept dropping and I saved thousands. In the same way I took a guess that a recession was coming, moved money from growth to conservative before it went down, and put it back once it looked like it had bottomed out. One day I'll get it wrong and lose, but not yet.