PBNs are not going to go away. Okay, let’s just get that out of the way.
If people want to set up high-quality, heavy-authority websites that manipulate links, PBNs will always be part of the mix.
What I'm reading into your question is whether obvious PBNs or badly constructed ones are dead.
If that's what you mean, then the answer is yes. They're dead today as they were dead yesterday.
But they're probably dying at a faster rate now because Google is quickly evolving.
It’s really important to make sure that, if you're adding new blogs to your PBN, the integrity of the existing network is preserved.
Unfortunately, if you buy PBN links, you're basically rolling the dice that the network won't get exposed.
But the problem is if Google is suspicious about one link, and the PBN is set up the wrong way, it can easily become a dumpster fire.
So well-constructed PBNs based on expired domains that have solid value will always be valuable.
But lower-quality ones that are sold like hotcakes? I'm not too sure about them.