@reu Western martial arts were
very much forgotten. We have the treatises, sure, but those haven't been practiced in their original form in some 500 years. That's why HEMA enthusiasts aren't so much "teaching", as they are "recreating" the style. Following the German traditions of longsword, messer, sword & buckler, and others, was a number of traditions involving the rapier; following those were the traditions with the smallsword, from which modern olympic fencing "evolved". Military saber, on the other hand, is an entirely different animal.
Comparatively, Japan had what's known as a "living tradition", where styles developed in the 1500s were still being actively taught, largely unchanged, into the 1800s. Kendo, itself, is a pretty recent thing, only being given that name in 1920 and only being conceptualized about 50 years prior.