There's something to that, but when an application and the libraries it uses don't agree on interfaces (ABIs, APIs, codecs, etc.) then the problem is unique to

There's something to that, but when an application and the libraries it uses don't agree on interfaces (ABIs, APIs, codecs, etc.) then the problem is unique to that project, and possibly that specific build of that project, so it's a little different than a buggy CPU. It's fair to try to simplify and tackle sets of distinct problems one at a time. Hence an abstract machine to assist in reasoning. But it's not the same as practical soundness or safety or whatever adjective people want to give. It's important to make that distinction because lightly technical people seem to ignore the subtlety here and think "well, it's a Rust program, therefore it's safe!". Reality is a lot more complicated. Unfortunately.