>>64144676
>why didn't they just build crossbows
cost

longbows outperformed contemporaneous crossbows
the keyword here is "contemporaneous": eventually they developed iron-staved crossbows which had about 15% more power than a longbow, and that was the end of the longbow

but before then, longbows had nearly the same effectiveness and were FAR cheaper
consider that at the time of the longbow's popularity, the 14th century, iron was expensive enough that most farm implements were made of wood, such as spades
better-quality (more expensive) spades were tipped with iron, which was salvaged when the spade broke and affixed to new spades
(remember old fairy tales about losing an axe head? yeah that was serious shit back then)
so at that point, crossbows were probably mostly wooden, perhaps reinforced with small strips of iron, and they would be expensive and wouldn't quite have the same performance of a longbow

when iron became plentiful enough that iron-staved crossbows could be mass produced, longbows were obsoleted