To extend on this good point--

DJB is not just a mathematician looking over theoretical equations. He's also an expert in the real world _implementation_ of cryptography where most security failures can be expected to occur.

For some mathematician's brilliant cryptography scheme, how easy would it be for implementers to develop constant time / constant power computer algorithms to avoid side channel leakage? Have these computer algorithms been developed, are they easy to implement securely or are implementers going to continually mess it up?

See [1] and [2] for answers. Summary: Technology is not ready.

[1] https://dl.acm.org/doi/10.1145/3569420

[2] https://dl.acm.org/doi/10.1145/3779208.3785290