It is very popular, has various content restictions and protections. Yet it should be used with care as not everything that is suitable for edults works the same way for children.
Good for video watching & sharing. But sometimes it provide unexpected related videos which we don't expect.
Good & safe, but not suitable for children,,,,,,
Youtube has a nice mix of youtubers. From those who reupload videos from others, to those who make fully original content. The videos want you to continue viewing, and even have you wanting to get on to Youtube another day to watch more. All in all, this site gets a full 100 out of 100 in my book.