Used to be the military was also worried about the noise of velcro. Everything was buttons or zippers.

Someone finally clued them in : 'If they are so close they can hear Velcro that is slowly torn off they are too close already and are going to hear anything you do'.

Most of the field gear today has some Velcro on it. It works.

If and when it wears out it is simple and easy to cut off the old stuff and stitch on new. It isn't much more trouble than replacing a button.

If anything, in terms of ease of field maintenance both Velcro and buttons are easiest. Zippers are a bit harder. Most snaps are a relative pain to replace. Many require specialized stamps and dies to install and when they get abused or replaced the burrs often tear the fabric so you need to start by installing a patch.

Given a life sentence on a remote island with no chance of resupply I would go with buttons. A bit of smooth hardwood or bone makes a workable toggle. Simple.