He has serious issues, no doubt. But he loves his country. He wants his country to be strong. That resonates with people.
And if we are being honest, a not insignificant portion of the Democratic base doesn't seem to have those two things in common.
Also, the Left, as even Bill Maher frequently says, are aggressively anti-common sense. They've swung so far out into the far reaches of nonsense with all the woke ideology that no normal, remotely traditional American with common sense thinks they represent him or her, nor have America's best interests at heart.
As far as Trump's issues, we're all aware of them. I wouldn't want to play golf with him or have him as a neighbor. He's loud, boorish, bombastic, and sometimes childish. However, he pushes policies that are good for the country, align with my views, appoints judges & justices that follow the Constitution, is tough on crime and border security, supports the military and police, and was great for my wallet and investments. I don't have to care what he's like in person. I care about what he gets accomplished.