The problem is that this guy got an opportunity. These days if you aren't an immigrant from the in-group preference ethnicities you are going to be expected to be perfect and even then they'll replace you with someone who admits they have zero experience in the field and there's not a damn thing you can do about it.

I have 5 years of experience in medicine and teaching and not only can I not get a nursing job anywhere despite the apparent "shortage" but I was replaced at a medical teaching job with a lady whose only experience was scheduling. They also kept trying to fill these teaching positions with minorities despite them never lasting for more than a few months because they sucked at their jobs or left.

How are people today going to do well if they go to school and the teaching is shit. They go to the workplace and the management is shit and won't hire actual talent or experienced individuals and rarely give chances to people that do have those. It's great that you acquaintance managed to get success but it seems more luck that he avoided DEI mandated pitfalls than because he kept trying. DEI has vaporized most people's reasons for continuing to try since you can try as hard as you can... they still want you replaced with their in-group ethnicity.