I had no idea ancient humans let pathogens develop resistance to the antibiotics we use today and casually let them spread in the environment, where they still reside in melting permafrost today. I should have guessed though, people never change and our ancestors were probably just as lazy and uneducated about these things. I really need to catch up on ancient aliens week on the history channel, there’s so much I’m still likely missing.

You laugh, but the fact is that our antibiotics mostly come from modern bacteria, which evolved those chemicals as a defense mechanism to be able to fend off territorial incursions by other modern bacteria. Most of the mechanisms that were useful for attacking million-year-old bacteria likely would not be useful against modern bacteria. Thus, those attack mechanisms likely would not have been conserved in their DNA over millions of years, or if they were, they would only be conserved in a tiny percentage

Except that's not how it works. The "arms race" between microbes isn't analogous to military technology.

Ancient microbes that have been dormant may no longer pose a threat to modern organisms, and so their defenses against those threats evolved away. Similarly, modern microbes that are not exposed to ancient microbes may not have had a chance to develop offensive tools against them.

A better analogy than "arms race" is probably something like rabbits. Rabbits seem like fuzzy little harmless critters, but the