Your comment seems to be about how these technologies aren't useful for us in the present. AFAICT, it doesn't dispute that the knowledge was lost.
An additional interpretation is that you're interpreting my writing as being from someone who thinks that "the Romans clearly built it better" etc.
That's not the point I'm making.
Yes, we have napalm and recipes for it. Yes, we have digital computers that are incalculably better than the Antikythera mechanism. Yes, we can trivially manufacture better concrete.
And that's amazing, for us today, but how much better would it have been if we hadn't forgotten about these technologies in the first place and had continued to improve on them? Heron of Alexandria described building steam engines, what if we had continued to experiment on them for over 2k years? Where would we be now?
The loss in knowledge doesn't matter (as much) anymore in the present, but it has held us back, measurably so. For a thousand years, between the Antikythera mechanism and a few hundred years ago, we somehow lost their equivalent of Kepler's laws, some version of calculus, precision machining, mechanical computing etc. For over a thousand years, we have no records of anyone producing devices that approached or surpassed its capabilities.
What if the knowledge behind that device hadn't been lost and we were 1k years further along into our understanding of mathematics and computing?
That's the point here.
The point is that those technologies were exceptional at their time, but were still lost, and we are poorer for it, because it took away hundreds of years of erstwhile progress that could have been made had we remembered and kept building on them.
Happy to hear how I could make the ending better though!