I think those bees learned how to fight them, which is probably untrue for the rest of the bee population elsewhere. There might also be birds that eat them.

I love having hornets on my property if their nest isn't located in a path I have to cross. They also eat wasps and you won't have any problems with them throughout the summer. They don't try to eat your cake or drink you lemonade and you can peacefully chill in your garden.

They always leave their nest after a season and it can make quite a mess. But nothing is better than having them in a remote location in your garden. It is better than any insect spray.

But you still might seriously want to get rid of them because they could indeed do a lot of damage in another ecosystem that needs to sacrifice several species until it adapts.