You need to think more about your model of trust. You will quickly discover that all security is built on trusting someone, even in the examples you mention abo

You need to think more about your model of trust. You will quickly discover that all security is built on trusting someone, even in the examples you mention above. You can compile your own kernel, but you trust kernel developers to not have put exploits in the source code. You can't audit the source code itself. You also trust your compiler to accurately compile the source code. You also trust compiler developers to not have put exploits into the compiler itself. You also trust the compiler they used to bootstrap their toolchain to compile the compiler. Fundamentally, all security is based on trusting somebody, understanding their incentives and intentions and weighing risk and reward. An excellent book on the subject is Bruce Schneier's "Liars and Outliers" https://www.schneier.com/books/liars-and-outliers/ https://www.schneier.com/books/liars-and-outliers/.