I used to use https://doc.new when I needed to write quick scratchpad notes, but it takes like two seconds for Google Docs to be interactable, and ends up polluting my Drive with a bunch of "Untitled Docs".

Lately I've used a bookmarklet that opens a fullpage contenteditable div which is instantaneous and worked for my needs. But I wanted persistence when I accidentally close the tab, and data-urls can't use localstorage, so I spun up quicknote.zip.

It loads in the blink of an eye, works offline, and stores each day to localstorage. That's all it does, take it or leave it.