In crypto, I wonder if the only safest approach is to roll your own everything except the crypto.

And if you get that far in knowledge and awareness, the crytographical aspect is an interesting challenge at that point.

Cryptocurrency and distributed consensus as a self-selecting domain of self-starters, in a sense.

Certain elctronic/software ideas--mesh net, peer-to-peer (P2P), ham radio, hardware hacking, self-hosting--may have that distinction too.