Imagine if every software was coded by this logic... nobody uses BMP images anymore? Just remove them from gimp... if users want BPM support, they'll use gimp 1.x. Security? Unencrypted http is insecure, just remove support for http from firefox/chrome... if users need to use http, they'll just uninstall the current version, backup their profile, install an old version, that doesn't support the lastest tls standards, open that website, copy the text they need from there into notepad, uninstall the old version, install the new version, restore their profile, open gmail and paste the text to an email... oh wait, you've missed something and need to copy some more text... whoops, back to uninstalling.
You would install Nix and run something similar to "nix run nixpkgs-23.11#openssh <address>"
export LC_ALL=C
nix-shell -I nixpkgs=https://github.com/NixOS/nixpkgs/archive/2322899a1fa85f6547004b2829af81e7b444f506.tar.gz -p openssh
ssh -V
OpenSSH_6.1p1, OpenSSL 1.0.0i 19 Apr 2012
Note that the first stable release of nixpkgs was in 2013.Also, ossified infrastructure is not a good thing. That's yet another problem we need to solve as a civilisation. Not everything new is good but some old things are genuinely inferior and should be replaced.
In the realm of operating systems and protocols, that sounds absolutely ideal. Microsoft has the right approach here.