Aren't there fees with Instacart?

Yes, the $99 annual fee plus a (say) $3/order fee (some are no fee). They also mark-up items at stores that will not give them a discount on orders. You pay one way or you pay another--but the customer always ends up paying. The idea is to pay to get what you want.

Instacart allows me to buy from any store on their list rather than have to go to each store and do my own shopping. Far cheaper than the $2k to $4k/yr cost of owning and maintaining a car, gas, and so on. Plus, I don't have any parking problems, tickets, tows, or worry about digging it out of the snow and so on.

I have three subscriptions for delivery: Instacart ($99), Walmart ($95), and Amazon Prime ($8/mo). All of which I can readily justify as being the lowest total cost vs alternatives (if there are any).

Used to have Shipt, but dropped it. Target management "went stupid" a year or more ago, so I dropped them. My primary use for Shipt was to buy from Target and have Shipt deliver.