Earning on YouTube gets harder every year. The platform enforces rigorous guidelines for advertiser-friendly content (Advertiser-Friendly Guidelines). A single careless word at the wrong moment in your video is enough for the algorithm to cut monetization (yellow dollar) and drastically reduce organic reach.
The most important point in YouTube's guidelines is the beginning of the video. If strong profanity appears in the first fifteen to thirty seconds, you can almost certainly kiss goodbye to ad revenue for that piece of content. YouTube considers this time critical because it determines the viewer's (and advertiser's) first impression.
YouTube categorizes bad words. Mild profanity used occasionally during the video (after the first 30 seconds) usually doesn't cause loss of monetization. However, heavy profanity, hate speech, or sexually offensive language used regularly throughout the video results in immediate ad disabling.