Cheaper isn’t always better no.

Which is why it is so impressive that the Falcon 9 is cheaper than the competition and more reliable.

SLS is still in early days so it’s hard to compare as it lacks numbers of reluability. But any rocket that has flown a lot whether it be the shuttle or even the might Soyuz. Falcon 9 is the most reliably rocket in the world and the cheapest.

If NASA can’t build rockets as cheap or as reliable as space X then I think the argument is that the SLS is a waste of money.