I always wonder why Jetbrains YouTrack never gets much mention, it's a really versatile system. Though the real area where it shines is where you have multiple projects to manage and teams of people who are spread across multiple projects.
If it's anything like TeamCity, their CI solution, then it has extremely confusing UI with thousands of options everywhere, and little possibility of controlling all that complexity outside of it's GUI.
You track is a little bit like that, I use teamcity to do builds of firmware, and I find it more confusing than youtrack. YouTrack is highly configurable which is a bit off putting at first, but, really, you should customize it for your situation, but quite often people want the out of box experience to be "perfect". But my experience of those systems is you quickly find you can't match it to your process and becomes limiting. But if your needs are simple, then YouTrack isn't necessarily what you want
Also worth noting not so long ago they introduced a simplified mode. Not sure how good it is for an out of the box experience.
I tried YouTrack a while back and it was super buggy, e.g. I would make a bunch of changes then navigate to another page and come back and they would all be gone. I just couldn’t trust it to not lose my work.
Because it has no app marketplace and targeted at tech people, not management. And management usually wins when they want everyone in one system. Also running both trackers is not an option b/c of the integration, licensing and support costs with little benefit for the management.