So my kayaks aren't tough enough. OK we'll use stainless steel, tough enough for you? It is just that our kayaks survive and give no problems and my partner tends to be rougher with her one than I am with mine.
As for glass, I find to fill a weave takes 3 times as much epoxy. Add that to both sides and we're talking weight. A kayak takes about 4 kg of epoxy. Now we're talking 12 kg plus the weigh of wood where as I'm talking just over that for a complete kayak.
If you want to talk to someone who is really weight conscious, try Paul Caffyn, circumnavigations of NZ, Australia, Alaska, Japan, Britain etc.
I will admit my kayaks have only been used on coast all round New Zealand plus the double doing a circumnavigation of Vanua Levi, Fiji. Holes? OK I did drop one from the ceiling on to the corner of a work bench and needed to do a repair.
I've only been paddling them for a little over 3 decades so maybe we need more time to test them?