Oh, I’m not asking how to download videos. I use Seal. I’m just pointing out that what OP said is true. There is a download button in the native YouTube app. (And, for the record, I don’t need an alternate YouTube app, either. I already have an alternate.)
It does have a download button in the Android app, but tapping it tells you to get YouTube Premium.
Use PipePipe.
Oh, I’m not asking how to download videos. I use Seal. I’m just pointing out that what OP said is true. There is a download button in the native YouTube app. (And, for the record, I don’t need an alternate YouTube app, either. I already have an alternate.)