Definitely a cultural thing, because a (US) biscuit is not very far away from a scone - but a Brit would think (a) scones go with strawberry jam (or cheddar cheese) and (b) a biscuit is a cookie, but hard - no eggs - to be consumed with tea or coffee!
Yes - 'biscuits and gravy' are very specific to the US. Not seen anywhere else in the world really.