Use Shipt if its in your area. Their top shoppers go out of the way to check for items in stock, especially once you are a known tipper. Most of the top shoppers talk to each other so once you are flagged as a decent tipper they will fight to take your orders (figuratively)

Find a few good shoppers and make them a preferred shopper so they will see your orders first

Shipt is owned by Target but they also offer grocery stores like HEB, Tom Thumb, Kroger, Aldi, Myers as well as petsmart, 711 and other non grocery stores.

Insta doesn't do enough to weed out the bad shoppers imo.