Why we dont have the DJI GS pro for Android ?

Because the sheeple don't like us

You're not missing much.   The waypoints are limited to 100, so if you're interested in 3d mapping, it's not going to buy you much.   DJI hasn't release any updates to DJI GS pro either.    Based on the videos I've seen on youtube,   I personally doubt you'll be seeing much more from this product.  They appear to have partnered with Dronedeploy to name.  That being the case,  it would seem DJI has very little incentive to  re-invent the wheel.  I'm not affiliated with either Dronedeploy or DJI.

thanks for your answer