Right, I grouped different dating techniques into a single point. All of them never consistently correctly dated materials of the known age, and in case of radiometric dating it was off by tens of millions of years. Talking about carbon dating, it still is based on a number of very questionable assumptions and any results not matching the official history are always simply discarded. Anyways, it was not the main point I was making.

Regarding the dark ages and lost knowledge, I agree with you. In that sense the official historic narrative does not explain a lot of different observations.