The sharpeners like that do a worse job than a good sharpening with a stone, but a better job than a half-assed sharpening with a stone (and really, which is more likely to happen on a weeknight?). I have knives from the restaurant, we used to get new ones weekly and send off last week’s to be sharpened, used a company Cozzini Knife Service - they aren’t designed to hold an edge as much as they are designed to be sharpenable. Have had one of them for almost 40 years now and I do run it through one of those pictured sharpeners pretty often if it’s not sharp sharp. Then wipe the edge, and hone, it works fine.
The sharpeners like that do a worse job than a good sharpening with a stone, but a better job than a half-assed sharpening with a stone (and really, which is more likely to happen on a weeknight?). I have knives from the restaurant, we used to get new ones weekly and send off last week’s to be sharpened, used a company Cozzini Knife Service - they aren’t designed to hold an edge as much as they are designed to be sharpenable. Have had one of them for almost 40 years now and I do run it through one of those pictured sharpeners pretty often if it’s not sharp sharp. Then wipe the edge, and hone, it works fine.