It's true, but we can make way better steel than Damascus steel, nowadays. We are better at almost everything than any past people have ever been. Do you know about anything a past people have done better than we know how today? That would be really fascinating.
The early Stoics knew propositional logic, and their successors didn't until the mid-19th century. (Source: https://www.goodreads.com/book/show/6380918-stoic-logic) Then the likes of Boole and Frege made it possible to see what they were getting at again from what survived -- which was, mainly, hostile reviews. Until then, anyone would've told you the current theory of logic was as advanced as it'd ever been, and the Stoics were guilty of arid pettifogging.
One thing Mates does in the book I mentioned is find translators' misunderstandings and prejudices, like the hair-sewing bit in the OP. That also comes up in Lucio Russo's The Forgotten Revolution about the sources on Hellenistic science -- classicists generally aren't scientists either.
(This comment is turning out to sound really hard on classicists, and I certainly don't feel that way. I'm just an interested reader.)
> Do you know about anything a past people have done better than we know how today?
This is a cheap shot, but preparing laserwort or dodo.
More practically, anything that is done by hand and needs a lifetime of training. But you need to be sufficiently specific. No one can use a longbow the way medieval british could, but anyone with a bit of training and a modern compound bow could probably match them. So you'd need to be specific to longbows.
At least one form of Roman concrete was better than anything we moderns had been able to come up with until we rediscovered the formula a few years ago.
