Boeing is having a rough time of it right now, with parts falling off its planes left, right and center. Just last week, a wheel came loose and smashed through a car, and earlier this year the door from a 737 Max aircraft broke off mid-flight. That mid-air disaster sparked an audit from the Federal Aviation Administration, which has gone far from well.
In addition to what the others said, I think the wheel thing was probably not boeing’s fault. That plane was delivered to United 22 years ago. It could have been a manufacturing error, but it was probably a maintenance error.