Everything is a matter of one’s own self control and maturity. I wouldn’t advise you allow a pre-teen, or teenager to have one. I certainly would advise to monitor to your best ability your kid’s account even if they are 18 because they still may be naive. But you have to use your own common sense.
I have a facebook account originally to keep in touch with kids I mentored, then it grew to family which is great because i can see pics they posted of the kids. But I don’t read every feed that comes in and I don’t go on it every day. There are times that two or three weeks have gone by and I didn’t open it. You have to filter. The pics with the feed are so tiny, you don’t have to look at them and you don’t have to get involved in everyone’s business. Keep it real folks.