Rookie electrical question

Moving the high current fire hazards to inside the cabin is opposite of how newer vehicles are wired. Relays keep large wires and 120 amps from their alternators outside the cabin. Everything inside is small wiring and fuse protected. You can walk around a yard like LKQ and find quite a few engine bay fires. The human beans didn't burn (pardon the pun).
My old Plymouth already has too much high current inside the cabin and not nearly enough fuses.