(Just like searching with / replaced 98% of my navigation)
Editing something without having to actually place the cursor anywhere is a killer feature
Also neovim can show you your substitutions live, no need for a plugin anymore. It's the default.
Especially as code is formal notation, such that it’s structured quite rigidly, macros composition can be seen as a meta language. Multi cursors is more suited for the “work hard, not smart”, like preferring litteral search instead of learning regex.