One of the benefits is using fzf autocomplete. E.g. in fish type the first char of the command and Tab to launch fzf. Then `,`+Tab is a quick way to filter these custom commands. Versus `ls ~/bin` would be a lot of characters for something I do a lot, or maybe I'd be going `ls`+UpArrow+UpArrow+UpArrow to autocomplete that first.