Peasants didn't have much mobility between lords, therefore they were seemingly coerced. Would anarcho-capitalism as stated necessarily play out similarly? Who knows.

The core of anarchism is the heuristic of rejecting hierarchies and coercion. A negative doesn't make for a compelling mass movement, hence all the different flavors are attempts at imagining structures that could replace the current ones. They all have obvious potential failure modes, but the core remains - downsizing the structures of arbitrary authority.

This is exactly my impression too. E.g. the OP article begins with characterizing anarchists as out of touch dreamers: Anarchists are simply people who believe human beings are capable of behaving in a reasonable fashion without having to be forced to. Judging by the name of the site it appears to be a positive characteristic too, which adds to confusion.