Project Managers are often the least useful people at my work. They mostly take valuable time away from you, while their contributions almost never impact the outcome of the software, appart for negatively, by either having it take longer because of how often they distracted the devs, or by having it be of ridiculous quality because of how little they understand characteristics of software maintenance and long term costs.

I've only seen them be useful when other teams or part of the company are waiting for things, and lots of cross team coordination is needed to align work, and make sure things are ready for the next one to start.

A PM working on a project who's only person waiting for it is the client/user of the software, is almost always a waste of everyone's time and the company's money.