Activity by apple

No. The Activity App activity can be viewed on iPhone IF you have and use Apple Watch. As I mentioned above, the Activity App is a companion app to the Watch on your iPhone. Your iPhone does NOT record activity. It just displays activity recorded on your watch.

See this link --> Use the Activity app on your Apple Watch - Apple Support

No, the Activity app is an Apple Watch app. It has a component on the phone to view the results of the data collected by the watch. There are many 3rd party apps for tracking exercise that use the accelerometer and GPS in the phone or that use other data collection devices (see apps from Polar and Fitbit, for example), but the watch has sensors that don’t exist in the iPhone, most notably the heart rate sensor.

The activity app requires an Apple watch to record activity.

Feel free to let Apple know your thoughts by providing feedback --> https://www.apple.com/feedback/iphone.html

Simple solution. The Activity App is a companion app to Apple Watch. Buy yourself an Apple Watch and record your activity.