Strap height should be based on how it affects your technique, helping you improve your playing, but sometimes artists get carried away and they focus too much on the aesthetic aspect. A lower guitar looks cooler and makes you feel more like a rock star, but it usually doesn’t provide the most comfortable playing posture.
When you are a beginner you need to hold the guitar in such a way that it promotes future learning, and it reduces pain and stress on your hand. Notes should be easy to reach, and if you think that playing bad but looking good is worth it, it’s really not in the long term.
It’s more important to learn how to play from an upright position first and then get to the aesthetic details. Let the guitar hang at a height that you feel most comfortable with when playing. Adjustments can be made after that.