I think the point is that since most people will charge at night, and capacity keeps improving, eventually if evs become really common, people will have less opportunity to buy something at a gas station.

That is definitely relevant, we don't know how much day-to-night load shifting will happen. On the other hand, there's also the probability that people who find themselves needing to charge during the day will often need more time than a gas fuelup would take, making them more likely to buy something. It's hard to predict what will happen of course, but those shop owners are going to fight to stay alive.

Wait until you have kids and are traveling. There is always a snack that was forgotten, a meal missed, or something left at home.

That's not nearly enough to support running a store.

Buying gas is a necessity, but also often an excuse to buy stuff on your way too and from work.

I imagine that they will have to invest in things that will keep people there longer.

For instance at the moment in the UK many supermarkets are putting mini stores in petrol stations.

However with electric charging taking longer, I can imagine that McDonalds might start buying up petrol stations.

It's very common already to have fast food outlets either connected to or adjacent to convenience stores at gas stations.