If most executables on your machine used Bun, then it would be a bundled shared library on your system eliminating the bulk of the 90mb executable size. Just like the shared libraries the 13043 .exe files on your computer are currently linking to.
Once again, that standard is nearly 5 years old. Microsoft has definitely continued changing their approach to OSS software. I think my favorite move posed by Microsoft that supports this is their open-sourcing of .net and working with the Mono developers to bring a better experience to all platforms.