what the benefit uploading hex file merely to arduino board? What the benefit of uploading merely hex file to avr based board like arduino uno Since the arduino ide it self will send intel hex file to the board after compile .ino file to hex file by the avrdude compiler (https://github.com/arduino/Arduino/wiki/Build-Process)?
If you want to upload the same sketch to many  Arduinos compiling it again and again would take much longer. Or if you create a firmware ànd don't want to disclose the source code, you can distribute it in compiled form.