One slight difference: fzf is cross platform, whereas I believe his solution is not.

Should be as cross-platform as Emacs and Bash are: very cross-platform. And the Bash wrapper (ezf.sh for ezf.el) could probably be rewritten in say Powershell.

Fzf is written in C, and there's a Rust implementation called skim (sk).

Each of these seem very cross-platform. But the advantage this solution has is that you stay within the Emacs ecosystem with Emacs syntax/keybinds/colors etc.

That would be fzy : https://github.com/jhawthorn/fzy