I understand why coroutines are an issue for saving, but why are they an issue for pausing? Don't you just not resume the coroutines while paused?

It depends. If you are using `yield return new WaitForSecondsRealtime(x)` then the coroutine keeps running when you set TimeScale to 0, but that's usually a feature and not a bug, since it lets you potentially use them when paused (since async/task C# stuff was usually been a bit sketchy, though it's definitely better now).

Some more info here (and in general about pausing in Unity): https://gamedevbeginner.com/the-right-way-to-pause-the-game-...