Kelly Loeffler was honestly a pretty good candidate!
This. Most of Loeffler's weakness is only obvious in retrospect. Being a self-funding woman with appeal in Atlanta's suburbs was a major strength for her, but she couldn't outrun Trump's delusional denial of the GA results.
Her other issues either didn't become obvious until it was too late or were forced on her by the rest of the GOP, like the insider trading scandal or her race to the far right to compete with that crazy idiot to make it to the runoff.