Parenting views on YouTube!

What's your view? 1. on babies watching YouTube 2. what is the age to start? Or how old did you start letting your little one watch? 3. How will you react if outsider comment something like wah so young stuck into tablet? Honestly I have not introduced YouTube to me baby at 1.5yo. and I don't think I will till maybe after 2 at least. But I do have parents telling me YouTube benefits baby hmmmmmm??? All parents lets share your experiences!