Turning Wi-Fi and Bluetooth off whenever you are not actively using them is usually unnecessary on a modern iPhone.
Apple designs both technologies to support features across iOS, including AirDrop, AirPlay, Apple Watch connectivity, Continuity and location-related services. Disabling them completely can therefore affect more than internet access or headphones.
There is also an important difference between Control Center and Settings. Tapping the Wi-Fi or Bluetooth controls in Control Center generally disconnects the iPhone from current connections rather than permanently disabling the radios in the same way as switching them off in Settings.
For everyday battery saving, constantly turning Wi-Fi and Bluetooth off is unlikely to be the most useful place to focus. Features such as screen brightness, cellular signal conditions, background activity and intensive apps can have a much greater effect on daily battery use.
There are still times when disabling either connection makes sense, such as troubleshooting a connection or when you specifically do not want the iPhone communicating over that technology.
For most users, however, leaving Wi-Fi and Bluetooth enabled allows iPhone ecosystem features to work as intended without requiring constant management.