I was motorcycle camping on very hard ground. I needed a hammer to drive them and still had much trouble getting them to drive in. One of four broke. Fortunately I found an old tire to use as a "stake." I don't have much experience and don't know if others would have performed better.
I was playing around with various tarp set ups today in the backyard and broke two of these. The ground was soft and I was pushing them in by hand but they still snapped. The bright yellow makes them stand out but two broken stakes on a trip could be bad news.