If you mix it with lizard tails and the breath of a unicorn you get a potion that will make anyone do your bidding or remove stubborn soap scum

It was (i guess still is) a home decor trend among (probably mostly white) women. Part of the "modern farmhouse" aesthetic.

Other than the spells you can cast that cause swelling in extremities, it's decorative/artistic.

Some people just want them to hang up and look at.

But you can use them in a lot of different ways, from turning it into stuff like hand crafted paper; to using it with resin to make objects. I saw a knife handle made out of a wasp nest some years ago. It's basically just plastic with the honeycomb paper for looks, but it does look pretty cool.

There's also people that try to use them to prevent hornets and wasps from building a nest nearby. It's supposedly a deterrent as the nest would make them think there's an established colony already, but it's mostly bullshit. Afaicr, the only time it would work is if the nest was essentially freshly taken so that the pheromones were still at full strength, and it would only work for maybe a week? Ish? I dunno, I read a lot of shit and if it isn't important, it fades fast. But I looked into that when we were getting a ton of wasps in the area, and the science just didn't support it working.