Was recently working in a mine that had issues with dust that gave off ESD. The workers were constantly shorting out there walkie talkies , and if you took a laptop or cell phone into the mine it was a good as toast. This was why we were called in . We were tasked with making a dust suppression system that would go ahead of the workers into the shafts and knock down the dust and eliminate the ESD. Rubber boots and gloves were the order of the day . It was so bad if you shut off your lamp and watched you would actually see tiny bolts of lightning crackling off your clothing as you moved around . That being said back in the normal work space that is my shop Ive never had issue with it when working on phones or computers and i never wear a grounding strap . My shop does not have any carpet and the air is never very dry As @dan says it has to do with were and when .