Some people think it is the greatest thing. Whatever works for a person I guess. I noticed in another comment, made mention about being on at least three sites. I think three are pushing it. Definitely at least two
I found being an active member of too many sites, is that your spending all of your time submitting and answering comments, that it does become too much. Two for me seems the ideal amount.
I am still a member of those other sites, only so I can see other artists who might not be a member here or on Instagram. But I don't submit artwork or anything like that on them anymore.