this paper is so funny [cw djb] https://cr.yp.to/papers/safecurves-20240809.pdf it starts off trashing DH, even though ECC and DH do not solve the same problem. then it gets incredibly cagey about prime fields:
There are other types of elliptic curves. In particular, there are many ECC papers that consider elliptic curves over non-prime finite fields. However, the SafeCurves criteria require prime fields.