It is pretty old, yes. Many people find relief from anxiety taking it. Doctors like it because they believe it to be not addictive. Many in the psyche community joke that it isn’t addictive because it doesn’t work. I took it for a short while, and it did help my anxiety, but it disrupted my sleep.
I say always go with an older drug if it works. The side effects are better known, and it is less likely to have a long term bad effect from the medication, because if there were any dire effects from long term use they would be known and the drug would have been pulled or black box warnings on the insert.