Trading is considered gambling because most people don’t understand it and most traders don’t profit from it. The truth is that you are risking something of value in an attempt to make money.
Trading is a learned skill just like flying an airplane. doing surgery, wood carving, etc. If you go about it the right way you can elevate your skill and make it work for you.
For an experienced trader who enjoys trading it is NOT GAMBLING. It is their full time job, a salary. For an inexperienced person looking for a get rich quick scheme it is gambling.