YouTube’s background media playback is a feature in both the YouTube and YouTube Music apps is typically reserved for Premium users who pay a monthly subscription fee. This same subscription also unlocks other creature comforts including ad-free playback.
Fortunately for jailbreakers, background playback and an ad-free listening experience don’t necessarily require an active subscription, as jailbreak tweaks made specifically for the YouTube and YouTube Music apps can lift the frustrating subscription requirement.