1. No ads
2. Free YouTube Music subscription (cancel your Spotify subscription)
3. Download videos and playlists to your device before a flight or other no-service scenario
4. Every time you watch a video, a proportional percentage of your subscription fee goes to that creator, no matter whether they are in a lucrative (i.e., ad-friendly) niche or not.
5. One less browser extension (or mobile app) I need to give permission to track my activity and worry it will be hacked or sold without me realizing it.