If you have ever downloaded YouTube in the past using your current Apple ID, you can often download a compatible older version directly from Apple's servers. Open the . Tap your Profile icon at the top right. Select Purchased (or "All Purchases"). Search for YouTube .
This is the most reliable way to watch videos without needing a compatible app or jailbreaking. Version Spoofing (Advanced/Jailbreak) Users on forums like youtube ios 125 7 download apk old version top