I don't understand why the article lists 4 issues, when 2 of them were solved in 2019: > pidfd is a great solution to the third and fourth problems So why tal

I don't understand why the article lists 4 issues, when 2 of them were solved in 2019: > pidfd is a great solution to the third and fourth problems So why talking about them? Is it just for proving the superiority of the author's own utility "supervise"?