The telephone network was famously thought to be impossible to bootstrap even 50 years ago. We won't ever be able to "black start" our computers unless someone cares enough to put money and effort into it. (Also all technological civilisation is somewhat self-dependent e.g. do you think it would be possible to make microprocessors without running computers?). Possibly reproducible build efforts and things like Guix will make it happen.
Last time I tried to build guix without substituters, I got hash mismatches in several downloaded files and openssl-1.1.1l failed to build because the certificates in its test suite have all expired. Bootstrapping is really hard, really valuable, and (it turns out) really unstable.