It’s only an issue on very hairy chests – i.e. full “bearskin rug” where you need to place the pads. There are patients that have so much hair the pads aren’t even touching skin.
In which case you absolutely need to remove the hair. A slightly delayed initial defibrillation is better than multiple ineffective ones. Most AED kits should have a spare set of pads (“wax the chest” with the first set) or a disposable razor.