>> Multiplication requires different units.
>> 2 baskets × 3 apples per basket = 6 apples
No it doesn't. In that example the "baskets" and "per baskets" (ie x/baskets) are cancelling each other. 2 baskets x 3 apples/baskets = 2 x 3 apples = 6 apples. Once you remove the unnecessary terms the actual multiplication is still basic repeated addition.
2 hours x 3 miles per hour = 2 x 3 miles = 3miles+3miles = 6 miles.