Why is there no audience option for people who watched 95% of the video?

Because Meta's API doesn't accept 95% as a view level for video audiences. The levels Meta allows, and Ads Editor offers, are: 3 seconds, ThruPlay (10 seconds or the full video, whichever comes first), 25%, 50% and 75%. If you need the most qualified audience of viewers, use 75%, the highest level supported. This is a limitation of Meta's platform, not of Ads Editor.