Honestly I prefer watching youtube over netflix and other things alike. I think Youtube is great for tutorials and other cool things but somethings on youtube you have to be careful about somethings that could be bad. So i'd suggest for younger kids you put a restriction on some videos and for all ages monitor account. So hope you enjoy.
Youtube has created this app so you can have cable tv for less and unlimited DVR storage, but as far a parental controls you might want to monitor your kids when they use it, if you want to know what they are watching it shows up in regular Youtube Watch History
This app/website is fine for any age, as long as you are careful. Little kids can watch their little TV shows, like "Baby Bum" or "Paw Patrol", kids can watch "DIY Back to school supplies" and "Best Hairstyles for short hair", then adults can watch "How to invest in houses" and "How to get pomegranate seeds out quickly". If your little kid is watching inappropriate videos, then youtube can become a problem, and should be monitored or some videos should be blocked.