If one uses encryption that has Perfect Forward Secrecy — i.e. knowing 1Password’s key doesn’t compromise the security of a particular session — you could make the argument that at least then an attacker would have to resort to active interception (more detectable) and/or dumping the 1Password process memory. And that’s in addition to the benefit of protecting against unrelated traffic captures, or other traffic-capture apps tricked into capturing 1Password traffic.

Still, yes, the benefit is minimal, and comes down to 95% optics and maybe 5% security (which may be too generous).