It's gotten to the point where I only feel totally comfortable using machines I've hardened myself.

My hardened laptop is an older Thinkpad laptop with LibreBoot to replace the BIOS, microphone and speakers and camera disconnected internally, removed the wireless cards, encrypted the partitions, and use Whonix as the OS. I've password protected the BIOS and it's set to boot only from the hard drive and I've also epoxied the screw heads in place as well as put globs of epoxy over all the ports other than USB in order to protect against hardware devices that can access memory through DMA vulnerabilities.

It was mostly an exercise in "how secure can I get". I'm not sure what else is possible.

If someone manufactured and sold a more modern hardened laptop, I would be interested in buying it.