Delivery is nice too, but the picking is what I really hate. Showing up, picking up a box, and leaving would be fine too. However, if delivery is the main option, I'll take it.
The fact that I strongly dislike Tesco and STILL just set up an account for grocery delivery so I can pay them to pick groceries and bring them to me, because I hate going shopping so much, suggests that this service is needed by at least some people.
I also wanted to use buymie.eu, but I have an aversion to services that would work perfectly well as websites but insist on an app instead.
Most people I know use it with an 'unlimited' subscription and feel the money they save, by knowing exactly what they will be spending and by not having impulse buys, plus the time saved makes it worth it.
Ocado might be seen as an exception but even that was started out as a partnership between Waitrose and another company (I forget which). I'm also discounting more niche services, such as Graze, btw.