Multiple Cursors in Emacs: Are they necessary?

;; Multiple cursors
;; URL: https://github.com/magnars/multiple-cursors.el

(require 'multiple-cursors)
(global-set-key (kbd "C-S-c C-S-c") 'mc/edit-lines)
(global-set-key (kbd "C-d") 'mc/mark-next-like-this)
(global-set-key (kbd "C-k") 'mc/skip-to-next-like-this)
(global-set-key (kbd "M-<f3>") 'mc/mark-all-like-this)
(global-unset-key (kbd "M-<down-mouse-1>"))
(global-set-key (kbd "M-<mouse-1>") 'mc/add-cursor-on-click)
(global-set-key (kbd "S-<delete>") 'kill-whole-line) ;;  Kill a line in Emacs

;; Search and replace
(defalias 'qr 'query-replace)
(defalias 'qrr 'query-replace-regexp)
(global-set-key (kbd "C-c x") 'replace-regexp)