Point of terminology, A binary star is 2 stars that are in orbit around each other. A double could be 2 stars in orbit or just 2 that happen to line up on the sky by chance like Mizar and Alcar.
You also get stars in 3’s (Triples), 4’s and larger groups. There are a large number of people who spend time observing double stars. Personally I am more of a cluster and nebula guy.