Didn't see it in the article but planks are just as good (if not better) with much lower impact.
“In the past decade, every branch of the U.S. military has begun to phase out sit-ups and crunches from their required testing and training regimens, or else they have made them optional, alongside more orthopedically sound maneuvers such as the plank.”
Crawls in all their variants have become my go-to exercise because they are great full-body movements, can be done on many surfaces(tartan running tracks are my favorite, at least for outdoors), are easy to vary further by adding slope or directional changes, and are simple to make loaded by wearing a backpack and stuffing it with weight(just make sure it doesn't fall out).
The point is that static exercise only builds strength at the particular muscular extension tested by the exercise. With planks your core remains weak for anything that doesn't resemble a plank, just as standing doesn't meaningfully improve your running.