Hiring so many PMs infantilizes the engineers and the designers who are perfectly capable of making good decisions, but just never had to because there was always a PM to babysit them.
The only argument for why you would want product management to be a specialist function is really it's a trade, not a qualification. It's something you get good at by doing. It's a muscle. But the flip side of that is the more you abstract your engineers and your designers from doing the same thing, their muscle gets underdeveloped.
Однако, очень важно не забывать, что индустрия нам поставляет разработчиков, у которых всё атрофировались или вообще никогда не выросло.