For rugged riders with a bit of wiggle room in their budget, titanium bike frames are arguably the best option out there. You can get a titanium frame custom-molded to your exact rider dimensions, and it will be beautiful to look at nonetheless.
Titanium frames are the premium version of non-carbon bike frames and are nearly as light and strong while maintaining many of the superior capabilities of a metallic bike. Titanium won’t crack or snap like a carbon frame will, and it will be ready for rougher and tougher roads for decades to come.