What's the one thing about your fitness routine that no app has ever tracked properly?

Not looking for app recommendations, genuinely just curious what gaps people have found.

I've used pretty much every major fitness app at some point and there's always something that feels weirdly missing or just done badly. Like the way most nutrition trackers make logging a meal feel like filing a tax return. Or how almost no running apps have any idea how you slept the night before, even though that completely changes how a run feels.

What would it actually take for an app to track your routine perfectly? Like what's the missing piece that would make you never need to switch again?