I wonder how much of this is company- or team-dependent. I don't mind sprints, but I also choose what to put on them myself with very rare (like twice-yearly, tops) requests from my manager.

I don't have a PM.

Scrum gives you (the team member) the power to decide what your commitment for the next sprint will be.

If you have a manger, that decides this, or the PO decides this, IMO that’s a key problem of your scrum implementation.