It's a fair point. I think the key in political contests is to win over undecided voters. You will never win over the Maga zombies. You probably won't win over "my family votes Republican" voters. But there's a chance with the almost impossible to understand undecided voters.
The people who thought "Trump is a businessman and we need a better economy" or "Trump is a billionaire so isn't subject to corruption" might see him differently now. Both of these takes are laughably naive but undecided voters tend to also be low information, last minute people. They get a vague sense of things and go with that. Seeing Trump humiliated on a money issue might do it.
That's just one scenario.
In some purple districts the vote margins are really narrow. A few thousand voters going D instead of R can do it. It's why third party candidates are so damaging.