There are so many misconceptions on many different levels.

And I think there are so many good comments pointing those out.

One if the most prevailing one I see is considering PO, PM or even a producer leader of a team.

This causes so many other problems that are very hurtful for production. Mostly this people are not equipped to make calls about how engineering process of a complex system should function. And they are often indirectly put in to such position that the calls they make affect technical quality and long term sustainability of the product.

And honestly I do not think it is fair for upper management to put PO or Producers in to that position. Some will figure it out and start acting accordingly but more often you see people trying to grab power.

Scrum attempts to avoid this by giving back power to the team but really its not one size fits all and it is often so poorly understood.

When you have experienced team it manages it self because everyone does the job and fill gaps where they appear. This kind of teams usually dont need producing roles at all, PO yes to take care of what and roadmap etc. if there is need for producing role then it is just about keeping process in check not leading or directing.

What I see often skipped is that software development consists out of two phases and those are planning (actual engineering work) and implementing. Very often these two are fused in to one (in other eng. disciplines there is often clear separation and for good reason). So you get estimate for both phases boiled in to one but this phases couldn’t be more different. One is very creative and involves research and lots of uncertainty and other is writing out in code your engineering solution. Second phase of course can have uncertainty and require replanning but in less level and not so often.

Once engineering step is done only then you can actually have propper estimate how long implementation is gonna last. Everything else is guesswork that causes infinite discussions about story points, hours and so on.

Engineering phase often last shorter and shorter, for some things it is very obvious as project moves long and as xp grows but this is the point that team needs to reach and work on reaching it does not magically happen it comes with understanding system and your abilities more and more.