Flying activity data metric units & calorie caount

It's been bothering me for a while. Why does Garmin show Flying activity data in metric units? Like kilometers? Altitude is shown in meters etc. Also, it treats the activity like a sports activity. What does the sweat loss and calories spent depend on? Is there any truth to it? Also I cannot see the average SPO2 and so on in the activity details after i fly.

Its surprising that nobody paid attention to aviation details. I guess you get the same data when you own a super expensive MARQ