For tech-savvy users, it’s possible to find an (not APK) of YouTube 125.7 online and sideload it using tools like:
(requires jailbreak) to change the app's version number in the Info.plist file to trick the app into thinking it is up-to-date. Helpful Resources YouTube for iOS 12.5.7 Download - Apple Support Community youtube ios 125 7 download apk old version top