There may well have been an element of prejudice, of suspicion. As in the Sunaks were just in politics to line their own pockets, with no real loyalty to the UK. It may have been a factor with some voters.
I think if the non-dom story had not broken, then Sunak would be PM now. It was either him or Truss, and they chose wrongly. Truss was not tainted in the same way by living next door to the Boris party bus during Covid. They were just desperate to avoid any more scandals or sleaze allegations - look at how quickly Conor Burns was dispatched, for fuck all really compared to the damage the Chancellor did.
But it's always going to be the Chancellor, FS or HS, isn't it? Party members are very reluctant to vote for someone who has not held one of the great offices of state. It's seen as the grounding for the premiership.