A useful payload for whom? Point me to someone who is willing to pay for such a bug and I'll believe you. Zerodium's old payout scale didn't even list denial of service, and to my knowledge no other serious vendor does either. If I can list a bunch of people who don't care about this surely you can find one who does.

That's not how vulnerability markets work. The idea that a broker would pay $75,000 for a phone DOS is very funny.