Going to a (small) supermarket is not a disadvantage, I find it a nice experience, because you can see/smell/touch) the products you want. I wouldn't buy fruits, vegetables, meat, fish, cheese, etc. online.
Not being able to take your stuff home is a little annoying, but depending on where you live it can be almost necessary to have groceries delivered. In Paris many buildings don't have elevators at all, or very small ones that can hold at most two people and not many bags. If you live on the 5th floor you're happy to get someone bring the bags up the stairs for you.
For me, it really depends on how reliable the market is. If I know produce and fish are going to be reliably high quality and fresh, I'd be more inclined to use an online service. However, that's not really the case with the average supermarket and therefore I prefer shopping in person. (If it were available where I live, I'd probably use Instacart with Whole Foods from time to time, but I'm lukewarm on using Peapod which is available for me.)
Not being able to take your stuff home is a little annoying, but depending on where you live it can be almost necessary to have groceries delivered. In Paris many buildings don't have elevators at all, or very small ones that can hold at most two people and not many bags. If you live on the 5th floor you're happy to get someone bring the bags up the stairs for you.