When you DO touch the Arduino board, FIRST touch/hold it by the large silver metal Ethernet connector. It is at "Arduino Ground" potential. Now YOU are also at Arduino Ground potential.
Damage usually happens by touching a pin first, and damaging internal chip circuitry.
Wrist bands, anti-static lab coats and ozone generators were used at workstations handling bare chips at IBM. But I've plugged and unplugged cards and processors in hundreds of PC's and handled hundreds of Arduinos and never AFAIK damaged one. But I religiously touch a grounded metal frame or object and handle the card or Arduino by a grounded part.
I did get get reprimanded once for yelling at an IBM service guy who took two memory cards out of my Model 95 and put them down on the carpet in my office. Probably had to do with the first word!!! in my sentence.