I work for a company that managed to keep an older and very incompetent guy for 15 years doing almost nothing; the guy was an IT technician coming part of an acquisition and they promoted him as manager at the time of the acquisition. I know him very well, I was probably his closest friend in the company: he was a very decent technician and a very nice person (that part explains the friendship), but not a manager, he did not ask for that and never wanted it, but due to legal constraints we could not demote him to technician, so he retired after being passed from one team to another every couple of years.

The same company, the same IT department, for 10 years no men was promoted but over 10 women were promoted. This is because we don't care about age, only about "diversity" so we don't hire and don't promote men. We have even cases where women in maternity leave were promoted (they were not active at that time, not even having a company laptop anymore) and also promoted someone who left the company after the announcement was made, so that the statistics of the promotions for that year would meet the targets. Strange thing, the 2 biggest pushers of these actions were 2 males, they had targets from above and did anything possible to exceed the targets (I heard them say they want 70% women in IT, we are just at 60%).