on rocky descents i spend a lot of the time thinking ‘ i hope that my wheels/forks/brakes/frame do not give way’
If I have time to do that, then I ain’t going fast enough.
If I don’t have confidence in a piece of kit it gets changed for one I *do* have confidence in.
I know I’m a skinny bugger, but (touch wood) I’ve never had a component fail catastrophically whilst “just” riding. I’ve broken stuff as a result of crashes (which is my own fault for not being good enough and crashing in the first place), I’ve broken minor parts whilst riding, but bar the odd chain, I’ve never broken anything that’s then lead to a crash.
That said my bikes are all sensibly specced for purpose, and I’m a relatively easy load case. Stick to sensible kit from reputable manufacturers and you should be fine.