It is true that wasps do not pollinate as well as bees, but they are very attracted to nectar and will carry out a useful amount of pollination in your garden. There is even one special kind of wasp whose sole purpose is to pollinate one specific tree. These wasps are known as fig wasps, and yes of course the tree that they are responsible for is the fig tree. The fig wasp is the only creature that works on the fig tree, therefore if there was no more fig wasp there would be no more fig trees.
Regardless of their less effective pollinating skills, wasps are without a doubt beneficial to your garden. They are hard-working and are incredibly effective at pest control. Wasps will spend the summer seeking out flies, aphids, caterpillars and plenty of other bugs that could be detrimental to your garden. The black and yellow wasp is already very familiar to us but many different kinds of wasps can take on the role of a pest controller. There are even solitary wasps that will hunt and kill insects for their larvae.
Many people fear wasps far more than they fear bees, but it is more than possible to live with wasps peacefully. Wasps will never be aggressive without reason. if you show wasps the respect they deserve and let them go about their work in peace then they will do the same for you. However, if you begin to wave your arms frantically around them to shoo them away or try and swat at them with your hands or even worse try and remove their nest they will view this as aggressive behavior. Another thing about wasps is that they are not slow to defend themselves, the moment they feel threatened they will attack, that is why it is so important that you give them no reason to view you as a threat. On top of all that, wasp venom has a pheromone that will signal to its fellow wasps that it is under attack and needs help so the chances of you getting stung by more than one wasp are very high. But again it should be made clear that wasps will not attack you for no reason, how a wasp chooses to interact with people is all up to the people.