I took half a dozen disk drives out of ancient computers from an elderly relative's house prior to recycling them. I could have tried to power them up, connect them to a working computer and used software tools to erase them but that did not seem to be a good use of my time. Instead, I put a 3/16" bit in my hand drill and drilled a single hole in each one through the platters. It was quick. It was fun.

I am satisfied that this is a suitable defense against any reasonable threat model. Worst case if I had done nothing at all would be the acquisition of a few decades-old tax returns. I think there are easier ways of collecting a few social security numbers, if that is someone's goal.

But I am curious. I suspect that state-level actors might actually be able to get something out of a platter with a single hole in it. Is this true? Are there commercial companies that could tackle this? How much would it cost?

I bet someone on HN knows the answer, or maybe even has experience with this kind of problem.