It still takes extra staff to make this happen. Normal grocery staff isn't just wandering around the store aimlessly; they're restocking and doing other administrative tasks. Most of those tasks don't just go away when you move to a curbside pickup model. You still need to hire and train more people to fulfill orders.

"they're restocking and doing other administrative tasks. Most of those tasks don't just go away when you move to a curbside pickup model"

This may be true in practice, right now, but do things really have to go to the shelves and then the curb?

They have to go somewhere. Perhaps if a store went to a curbside-only model they'd organize things in the store based on popularity so the people fulfilling orders could be more efficient, but it still takes people working throughout the day to make that happen.

Many of the stores offering curbside, like Wegmans, are using Instacart shoppers, so it's not taking away store employees per se.

Sorry. Looks like I misunderstood that, I thought it means that they put it in front of your house.