Supporting pre-compiled native binary packages. Look at the manylinux effort for eg: https://github.com/pypa/manylinux, which spans a decade to ensure that glibc changes did not break python wheels. Every other language required a full-build pipeline for binary extensions: node-gyp for eg. Even where it was supported (such as PECL), compatibility with the language and system was always left as an afterthought and underspecified. The end-result was that the only way to "safely" install binary extensions for most languages was via distros or third-party repositories, but never via the package registry.