If you eat at a restaurant more than once, it's both customary (not "bonus points" but the norm) + a "don't spit it my food" insurance if you return. If I withhold tip I'm never coming back, whereas if the food is just that good I'll grit my teeth and tip.

Driver tips are unrelated. Sure I've felt bad the single-hand-counted times I've gotten "bad service" but the other 97+% of times they do the normal thing: deliver somewhat on time. Just tip before and stop whining.