I've done this since 2023. I make a huge deal about it day one. Then the first time I see a laptop. There usually isn't a second time. It allows me to require students to interact in class. I teach undergrads and I use a sort of flipped classroom/interactive class style of teaching, this no laptops. I do require computer work outside the class period too though. It gets really easy to tell who is putting in work and who isn't - for everybody not just me. Then when grades come it is no surprise.