I don't like Trump and I didn't vote for him, but I didn't vote for Harris for EXACTLY the reasons your US friend listed. It is not rocket science.
Trump won in 2016 with a very similar message. He understood people were not happy with the way the country is going, and promised change.
I don't think Trump brought any real structural change to the US in his first term. But he did shake things up.
The fact that horrible corrupt people hate Trump is his most redeeming feature.