I can only speak for myself here, but for me having Blink means that I can travel for a week and not bring my laptop. Other apps like Prompt were pretty decent, but Blink has brought all the pain points (compared to my Macbook) to (almost) zero, through faster rendering and its amazing support for shortcuts and remapping the keys an the Smart Keyboard. I mostly do development of numeric software, so even when I'm working on the Mac, I'm always just connected to the development server or cluster nodes, with tmux + vim.

There is the iPad Pro for example. With a 4G connection and a decent terminal, it could be quite useful for managing things on the go.

There's also just the scenario that I don't have my laptop but could really use an SSH terminal and CLI environment at the moment.

I occasionally use Prompt. It's for when you get a call about something being broken and you're on a train with only a phone, not for scheduled work.

With an ipad, tmux/emacs/vimand an external keyboard you can use this to actually work without drawbacks and without carrying a laptop around.