I use the visual-multi plugin [0] all day in vim/neovim.
I don't like using tons of plugins but multi cursor with with selective invocation like the ctrl-d of sublime etc was the main thing I missed when moving to vim. (I use visual block mode too but it's not the same thing).
They are very useful! As a long time Vim user who switched to Kakoune[0] a while back, I didn't even realize I needed a good multiline cursor from my editor before it tried Kakoune. Highly recommend it!
If you need to pass lots of arguments to a command it's super useful. Typically I don't do this because it's quite unwieldly with a standard readline editor, but I could if multiline editing was available!