I know a few people who use them. Exclusively young, techy parents with infants or toddlers. Use them to order critical, always running out baby things. Like diapers. Basically its easier for them to tap the button when they realize they’re running low. Than to forget to make a note of it because things are so hectic and actually run out.
It has created a situation where mom realizes they’re low on something, hits the button. Dad realizes they’re low on the same thing and hits the button. Mom again realizes they’re low on it because it was 4 am the first time she hit the dash button. In a sort of feed back loop. And now you have more diapers than you can physically fit in your apartment.
So they tend to get retired when life calms down. I think a lot of them switched to the whole subscribe and save thing too.