When I see a Sysco truck delivering to a restaurant I tend to start avoiding it

Not necessarily the best idea. Often they are the only dry bulk(flour, etc.) or paper/plastic distributor that a restaurant can access. See if they also get deliveries from others before jumping to such conclusion.

Restaurants hate Sysco just like you do. They deliver late, get it wrong every time and argue about rejection when half their delivery is destroyed goods.

I could see that in many places, but I tend to live in the largest urban areas. I see lots of local distributors around.

I've worked at Michelin starred restaurants in major cities that ordered paper products as well as commodity items from Sysco. Like I said, it isn't a particularly good metric.