I was more thinking of scripts, yeah, like you describe.
Where I get hung up is, if I need to keep the traditional syntaxes in my head for scripting, why bother storing another one in my head for interactive use?
...that said, I do use ag and rg for other interactive tools, like cross-project search in Emacs.
And my own systems have automatically synced dotfiles, making it mostly a non issue. (I'm using Syncthing for that)
When writing scripts I usually fallback to traditional shells/commands for compatibilty. Unless I'm really sure I will be the only user.