You see a lot of people start a successful business, and then fail at their next venture. That doesn't mean they're incompetent. Everyone swings and misses sometimes.

But, if there is eventually a patten of failure, either luck was a factor, or perhaps the person themselves has changed.

Bill Gates and Paul Allen were virtually the the only high school students in the entire USA programming on microcomputers when they were in high school. Bill Gates mom regularly sat on IBM boards and advised him regularly in Microsoft's early years. Finally, even though Paul Allen wrote a 12,000 line chip emulator in assembly that was essential to Microsoft's existance, Bill totally threw him under the bus when he had to take time off the work to deal with (checks notes) life threatening CANCER.

This is the type of unicorn ruthless capitalism that it takes to become the richest person on the entire planet. Quite honestly, Gates gets less hate nowadays because of his philanthropy and the fact that there are even shittier billionaires.