alt Hacker NewsIs it though? There is nothing you can solder onto it that will gain any meaningful access and go unnoticed. Tampering with the supply chain is a lot more difficult, easily detectable, and wouldn't scale. I can use 100% open source software, in an OS where it's signed and completely safe from interference - except the NSA of course, but they are not interested in your money.
For example, in MacOS it would be extremely hard to "sniff the display" as in this attack, unless you take obvious steps to authorize screen access.
Using a consumer pc, risk wouldn't come from hardware hack implementations, it would be mostly software.
To continue with your example, "display sniffing" could be done by infecting trusted software or software presented as trustworthy (fake or infected Zoom binaries, Xcode binaries, etc.) or injected through open source dependencies like npm packages.
Yes, you or I might be paranoid enough to check the checksum hash to make sure the open source code matches the build. But every time, for everything?
The less connected it is, the safer. The less software it runs, the safer.