It’s hard to know where to draw the line, and the Catechism being so vague on the issue doesn’t help matters either. I try to avoid patronizing non-essential businesses on Sundays as much as possible, such as department stores, the gym (ok, so I avoid the gym the other 6 days also but that’s beside the point), hair salon, etc, because someone has to work in these places when there is no need.
But with restaurants, I’m not sure. Seems essential enough for at least some restaurants to be open, for those of us who don’t cook and have children who devour 2 burritos and get hungry again 2 hours later. It seems the same as the grocery store - sometimes you run out of an essential and can’t wait till Monday.
I also wonder about businesses that aren’t essential, but that provide relaxation and recreation that seems suitable for Sunday, such as the zoo, ski resorts, theme parks, etc. Maybe if I remember I’ll ask a priest for his opinion.
Definitely the way Sunday has become just a part of the weekend in our society is sad. I went to Walmart on a Sunday once while on vacation in Salt Lake City, and the place was deserted. It was so refreshing, made me realize that’s how it should be, this should be our normal.