AMD will almost certainly have something more up to date than your motherboard manufacturer.
It seems a bit silly including a DVD full of drivers in the box with a motherboard these days, but the idea is still the same. Once you've built your PC you want to make sure you've got the latest drivers since (usually) that's where improvements come from.
In particular, if you're building a new Ryzen PC on an X470 motherboard, AMD will almost 100 percent have more up to date chipset drivers than the ones your motherboard manufacturer is offering up.
Full story from the WindowsCentral blog...