The problem with that is that it would require a huge amount of coordination for it to be by design. I think it's better to look on it as systemic. Which isn't to say there aren't malign forces contributing.

I agree. Perhaps, "by design" is not the correct phrasing. Many decisions and effects go through a multi weighted graph of complexity (sort of like machine learning).

Indeed. How does that saying go? Don’t attribute to malice what can be explained by stupidity?

On the other hand Microsoft and taceboook did collude to keep salaries low. So who knows.