When you download an IPA outside the App Store, you are bypassing Apple’s code-signing and security checks.
There is only one legal way to get version 15.02.1 on your iPhone today: youtube 15.02.1 ipa download
Have you successfully installed YouTube 15.02.1? Share your experience in the comments below (but remember to never share download links – they violate our safety policy). When you download an IPA outside the App
YouTube 15.02.1 IPA, download YouTube IPA, sideload YouTube iOS, YouTube 15.02.1 features, IPA safety risks. YouTube 15
: If you previously owned YouTube, go to App Store > Profile > Purchased and download it; iOS will often offer to download the last compatible version for your device automatically.
The risks of malware, account bans, and app instability far outweigh the benefits of a nostalgic UI. For 99% of users, the best path is either (supports creators) or using a modern, open-source sideloaded app like uYouPlus.
If your iPhone is jailbroken on iOS 14 or 15, you can use to permanently install YouTube 15.02.1 without resigning.