Actually, it does mean that, because the side effect of a high risk niche is that chargebacks tend to be higher. Not are, but tend to be.
Just from a basic risk evaluation perspective, you can intuitively know that selling purses for example should have a lower chargeback than say adult entertainment.
But at the end of the day, this is what NAICS is for. It's not a guessing game.
It's far from a myth, I've provided high risk accounts all the way up to 4%.
If that's a myth, then so are all the casinos...
And no payment processor in their right mind will show rates on their website. Guarantees come after the preapplication.
Otherwise you'll become a hot target for bad characters left and right. Then you'd fuck your risk portfolio and end up like Stripe, shooting first, then asking questions later.
Those kinds of merchant accounts are invite only man. We are not a fan of inbounding.