I believe most people here will agree with that statement; nonetheless the problem is the ludicrous situation some people view the world through and consider that "junior techie moves to senior manager" as a fact of life†.
There is real social pressure on that front and lots of belittling of tech. Basically every time I meet some new person and say that I'm a software engineer, I get asked "But you still code at your age? Surely you'd rather manage people! What have you even achieved in life?" or any variation thereof and have to explain, justify even, that designing, planning, architecting, maintaining, and developing software is a real expertise domain in and of itself. The situation extends even in the workplace, where it is mostly expected of you to raise to management positions, and you won't get any raise if you don't "move past" "coding", as coding is largely considered a menial task by many, a sort of weird heritage of/transposition from an industrial culture.
† This has a vicious side effect of creating an ecosystem with mostly zero-quality software, since somehow only juniors and unskilled seniors code, because either skilled coders raise up the management hierarchy to get some raises, just leave for places/countries with a better mindset, or are overwhelmed by their unskilled peers.
And there are also skills (or attributes) that makes you both better programmer and better manager: being organized, systematic, being responsible, willingness to do also boring tasks, understanding what people say when they talk to you, ability to explain yourself, good memory, etc.
The problem is viewing the company as hierarchical. Just because less managers are required doesn't mean it's a more important role.
What I was saying was that just OK engineers can get promoted to management and actually be quite good at it.
But I also don't consider a product manager higher in the hierarchy, at least not explicitly. Does a PM get paid more than a mid-level engineer?
More thoughts on the semantics of mediocrity (the author was also referred in a sibling comment) https://www.ribbonfarm.com/2018/04/24/survival-of-the-medioc...