Yup, while they don't collect pollen, they do visit flowers to find nectar for themselves. They inadvertently transfer pollen from plant to plant.

No, the idea is that bees are useful because pollinators, and honey.
However, wasps may not be the friendliest creatures around, but they are certainly useful too - like cleaning up corpses, leftovers, and last but not least they eat insects that we think of as plagues

Check out the book (or audiobook) Endless Forms by Seirian Sumner! It's a fascinating exploration of the different kinds of wasps and their role in their environments. For example, some figs can only be polite (typo: pollinated) but a certain species of wasp and some wasps use antibacterial compounds to coat their nests.