In order to avoid destruction, he even chose to live a long life of isolation from the world.
As for Doctor Pym, it was even worse for him.
Due to prolonged use of Pym Particles, his body had begun to deteriorate, forcing him to minimize their usage as much as possible. Because of this, Ant-Man has long faded from the spotlight and is no longer active.
Whether it's Banner or Pym, both are experts in their respective fields. Although their overall capabilities might fall short of Tony's, they possess expertise in areas that even Tony can't compare to.
They each have their own pride.
If it were anyone else offering them such a promise, they would surely scoff. But this mage before them? He had once performed techniques in Hell's Kitchen that were nearly divine!
If it's him making such a promise, especially one involving magic, it indeed seemed highly plausible.
