Farid Zakaria recently gave a talk¹ (at NixCon 2022) where I think he put it better: Nix (and Guix) blur the line between dynamic and static linking.
I think this is true, because with Nix and Guix, you actually have an end result with the positive characteristics of both kinds of linking.
His talk, based on his work on shrinkwrap² and nix-harden-needed², called for the creation of a new executable format for the Nix world. Seems apropos as a reminder that there are other possibilities!
(I think these kinds of solutions are definitely within reach for Valve from a technical perspective. Other tools are using them today.)