Well, there's a few aspects to this. There's an internal issue tracker. Maybe more than one (I'm not staff, but I'm aware the issue tracking system has changed, and I don't know if community, 'public Q&A' and teams are independent or different projects on the same platform) - and a lot of what we do here does have hooks to that. Certain tags, like status-review tie into it.
Having worked with an issue tracking system, both professionally, and occasionally as a moderator (teams has one that's exposed to its users, and the moderators have a team we use for knowledge sharing) - meta has a few advantages in this context.
Practically - it significantly reduces the effort of creating an issue, and done 'right' allows for a non bug issue to be workshopped and polished before formally being taken up. It provides a low friction venue for people who do use the Q&A to raise an issue in the same format.
Many issues are also resolved at the moderator or community level, either cause staff involvement is not needed, or it is something that doesn't quite fit the 'traditional' use of issue tracking, and it allows for a certain level of flexibility in how things are handled.
On a user level, we use meta - per site or this one as an issue tracker. Its built into the site, doesn't need a separate platform or log in and has better visibility than a 'proper' issue tracker.
I wouldn't say its perfect - not all staff are comfortable with meta use, and the company has lost/wasted/undervalued some of the best folk at it as well as the competencies involved in my opinion.
Meta works for us because it reflects a crucial part of SE culture - meta is open, and while there's a learning curve, is a way to build ties and understand the needs of the end user. Someone once described Stack Exchange as Social Software - Meta very much acts as an issue tracker with other tools depending on need that reflects this community focus (ideally anyway) .