For a lot of people, we're well below the level of security where hardware security is relevant. The average person is still willing to run software that downloads/installs/runs malware on their machine (browsers with Javascript enabled). So in that sense, we've got a lot of work to do to get developers and consumers to practice better security at the software level before the hardware level is even a significant concern.

However, I do hope for a future where software security is both a fairly solved problem and the norm, and if that time comes, I want to be ready for the inevitable arms race when hackers move to hardware vulnerabilities.

Recognize that yes, there are always more layers, but each layer of vulnerability has decreased capabilities. It's a lot easier to read someone's hard drive using an installed app with full filesystem permissions than it is to read the same hard drive using their power supply.

Also recognize that these layers require more capability from your attacker. A Russian hacker can write an app that reads people's hard drives from anywhere in the world. The power grid simply lacks the networking infrastructure for long-distance remote access in many cases, requiring more physical locality.