I for one, am the first to question the existence of PM role at all. Ideally, people who are designing the solution from grounds up, coding it should be the people who can demonstrate its value to users. Unfortunately, it rarely happens, at least in my experience. Engineers speak a language riddled with technical jargons that clients get lost within first few minutes.
In case of B2B product management, usually initial few discussions with clients are on articulating business benefit, our understanding of market, competition analysis, relaxing of contract terms. Only after these discussions, clients bring in their tech people to understand tech aspects of product. So, I would be happy if engineers can carry all kind of conversation but usually they don't.
As for ML/AI engineers, sure they have understanding of data. ML models alone are useless. Models exist to solve a business problem that existing technologies can't solve. Now, what should a ML engineer spend his time on, perfecting his model or understanding business context under which this model will bring revenue.
Like I said, an excellent PM would be someone who knows tech inside out but can also correlate it to business priorities. It's not a "gut call" , it is just the ability to cross relate insights. No rocket science.
By the way, if you think PMs are useless, what do you think of management consultants???