> To say one is more powerful is really false. I think recursion is great, and for some situations it should be the go to method, but anything you can write iteratively you can write recursively and vice-versa.

I mean powerful in a strict theoretical sense. Without using a way to freely allocate arbitrary memory, recursion can compute things loops cannot. The ackerman-peter function is an example.

Loops however can be trivially converted into functions.

Therefore because loops can be converted into recursive calls and recursive calls cannot always be converted into loops. Recursion is more powerful.