Why does the Bible portray angels with human designed weapons?

Why do angels have swords, which are ancient human weapons, designed for hacking at human flesh?

Consider that the Hebrew Bible was written during the “sword era.” For thousands of years of human history, men fought with blunt clubs and stone axes, then when the Mesopotamian civilizations discovered copper-working, swords were invented, and the Bible was written in that sword culture. Thereafter humans invented various forms of weaponry, and will surely continue to invent more. Yet, none of the weapons before/after the writing of the bible are carried by angels.

 

Why do spiritual beings need human weapons for cutting physical flesh, if they have immense supernatural powers and can wipe out human armies with a blink?

If it’s all about symbology, would a modern angel carry an assault rifle?