No. I use Sainsbury's (for deliveries) and don't have more money than sense - IMO anyway
. Others may take a different view of how much sense I display.
I use to use Tesco as they were the first to offer delivery in my area about 25 years ago. I changed to Sainsbury's as there is no Tesco near where we shop when we visit our lodge, and I was running 2 points cards, so I decided to amalgamate and switch to Sainsbury's for both. I didn't notice a difference in price or quality - they are much of a muchness.
If I run out of supplies, my husband tops up from Morrisons as that is the local supermarket. Again, pricewise it is similar, but they don't have the range of either Sainsbury's or Tesco. If I am in the town centre I use M&S, which has a better choice of ready to cook things, but is a small branch so I wouldn't do a week's shop there.
I don't see Sainsbury's as a fancy store - just a standard supermarket.