I honestly thought Stirling's "The Change" from the Emberverse series was pretty good.

An enormous electrical storm of unknown properties encompasses the island of Nantucket and transports it back to the bronze age. The resultant time shock causes everyone on Earth to suffer an intense migraine at the exact same moment. The far more important consequence is that any device run off of electricity, gunpowder, explosives, internal combustion or steam power ceases to function. Permanently. In a single instant.

Some underlying physical constant changed. No fae magic involved. Hypothetically, you can use the scientific method to identify why and get back to driving tanks and dropping bombs. Unfortunately, the tools you would use to identify what changed were all disabled too, so you have to bootstrap yourself in a world where you can't figure out how to get internal combustion or electricity to work.

Millions of people have enjoyed the Emberverse books, they are hard sci-fi without an explainer, and I don't think you as DM need to hold yourself to a higher standard than that.