IMO Jira is the epitome of a tool being what you make of it. If you keep things simple and pick the slice of features that work for you, don't go crazy with plugins or creating extra ticket fields or mandatory workflow restrictions, you'll be fine.
If you have multiple PMs each trying to impose their own view of the world expressed in ticket form, it'll be a fiasco.
Very true. I am a reluctant user of JIRA, and once I was past the realization that JIRA isn't meant to be used out of the box, but rather meet your process and production where it is, it kind of fell into place, and there are few pieces of software that can remain straightforward in one area, and be good at absorbing details and complexity as things pop.
If you have multiple PMs each trying to impose their own view of the world expressed in ticket form, it'll be a fiasco.