Achieve quickly what they labored long and hard for.
This is guaranteed to enrage some set of people. Even if your success is not overnight, if it appears you achieved it quickly, or with fewer hoops than most in your field, they will not like it.
You see this play out all the time.
Someone without credentials makes a claim that gets a lot of attention. Angry responses from experts are mostly, “You’re not a real X”, “You need to engage the literature”, and, “You don’t know what you’re talking about.” Not arguments in response to the claims themselves, just anger at the one making them and the route they took.
Someone writes a best-selling book on a topic where others labor in obscurity. How dare they appeal to the crass common man instead of publishing through the guild!?
If people accuse you of doing something you have no business doing, they are probably threatened by you. Not so much what you’re doing, but the fact that you did it without their permission.