Vent: my old foreman swore by a wet line, but a dry line saved my wall

Back in 2019 I worked under a foreman named Dale outside of Columbus who insisted every course gets checked with a wet line pulled tight. He said it never lied and that dry lines sag in the heat. I followed his rule for two years, and it cost me a few wavy spots on a storefront job that the owner noticed. Last month I was on a garden wall with no one to hold the line steady, so I went with a dry line and a string level every three bricks. The wall came out dead straight, and I checked it with a 6-foot straightedge afterward. So now I'm wondering, is a wet line really better or just what old guys repeat because they learned it that way? Has anyone else switched methods after following a trusted mentor and seen a different result? My next job is a curved retaining wall, and I don't want to mess that up with the wrong approach.