> Somewhat off topic, but I’ll bring it up anyway, it must have been better to have lived in a Gallic or Germanic or Iberian tribe than to have lived as a Roman citizen if they were willing to die than submit.

Peoples conquered by Rome did not become Roman citizens with the rights and privileges associated with that, generally.

In the graded levels of rights in Roman law, depending on whether they were just conquered or had treaty status, they were two or three steps below citizens of Rome.