plain text is a wonderful thing, overtaken by rich text formats like .docx.

rich text brings in new things to the table, such as easy text formatting (bold, italics, stabstrikethrough).

but plain text, can do those things too though. and without fancy software. if you have a markup language, you can do anything with plain text.

markdown is a big hitter. just with a couple symbols (and maybe some html if markdown doesn't let you do something like changing the font size), you can format any text without memorising where the formatting buttons are on ms office's word. it makes writing faster and easier. and if one wishes to turn that into, say, a .PDF file, they can simply use (something like) pandoc. with one text file and one command, one can create a nice formatted PDF file in a couple of seconds.

another 'markup language' (although maybe you wouldn't really call it that) is todo.txt. it aims to let you make a digital todo list with text only, and still be legible (instead of that text editor window that just has 'eat the moon' written on it).

it's just amazing what plain text can do, as opposed to what google keep (or any other fishy random note app) can do.