Resource Packs not using inheritance if a item uses default resources and not custom

I am creating a resource pack and assumed that if i use the /block location for textures then when people with different resource packs saw it, the blocks/items would change accordingly, it appears that it just uses default vanilla packs regardless of the pack your using.

I am unsure if this affects other versions but it might as i don't think resource packs have been changed all that much from their implementation.

Attached is the resource pack i use, if you place a rail which uses vanilla textures and load in other resource packs it doesn't change with the resource pack inheritance