In your desert island scenario, you need to survive long enough to become acclimated to your new environment. Whether or not you learn to adapt will not be hindered by good EDC and may be enhanced because you have bought yourself a period of adjustment.
Oh yes, certainly. It's going to be a textbook case of natural selection: The weak, slow and unlucky will die out, leaving behind the strong, fast and resourceful, as well as survivalads
. Now, where as the latter will be perfectly content with camping, as their ample supplies allow, the former may well start building a house, herding local animals and merging into boyscout troops with the rest of the island brigade.
Basically, I am talking about the fact that lesser stimulation (in the form of lesser stress, "bought" by prior preparations) might result in a less active response from the survivor and, consequently, a lower level of general achievement than would be possible otherwise.
It doesn't even matter if you've read this and said "okay, now I'll try to rely less on my gear", because the adrenaline is simply not going to be there.