What are you folks doing that requires roadside repair, or even trailside repair? I have been riding bicycles frequently since Christmas Day 1964, and I have only been stranded by a mechanical twice in my life 1: Mountain biking, chain got wrapped in the rear wheel catching a little air. 2: Mavic Ksyrium wheel broke a fancy proprietary spoke. I have never broken a chain, I have broken 3 spokes on my own bikes in all those years.
Reliability starts at home, knowing how to maintain your machine, knowing what componentry will work reliably over the long haul.
Learn how to shift and properly install a chain if you are having problems in that area. I carry a chain tool most of the time but have never needed it.
Your big 'ol educated brain is your best tool ever, millions of years in development.