They were barbarians because they sacked Rome with violence.
If a person smashes up a signpost, mailbox, or telephone pole, would you call them civilized or barbaric?
Barbarism is as barbarism does, and what it does is destroy signs of previous civilization.
No this is not me being elitist, this is me saying things as they are. It wasn't "migration". They helped destroy Rome!
All cultures are not the same! And even though Germans later adopted post-Roman civilization (Muslims never have become civilized, because their stupid religion is actively at odds wuth civilization, blaming it for all of their problems), the fact doesn't change that a roving gang of thugs is not an "immigration." This is why the West is falling apart, we can't even figure out the difference between immigration and slow invasion.