I used to use Google Docs and Pastebin for RFD's and then post the link to the Google Doc or Pastebin in the voting box.
However, some problems with Google Docs was that I would have to create 2 separate versions on the Google Doc: one for computers, and one for mobile/smartphone users, since viewing a Google Doc on the smartphone that was meant for computers would show the words all over the place and you would have to scroll left or right in addition to having to scroll up or down to read the whole thing.
For example, this is an old archived RFD of mine for a debate: https://web.archive.org/web/20191029125616/https://docs.google.com/document/d/1KH8aLtYjkA6NqmtadVzCJGbHOOpC_wMk8rohKLa5kBg/edit
Normally when I click this link using my computer, it shows up normally like this: https://i.imgur.com/uC8kG6P.png
However, when I access this link using my android, it shows up messed up like this: https://i.imgur.com/mGZktfZ.png
The worst part is, on my android, I can't zoom in or out, so I'm stuck having to start at the left, then scroll to the right as I read, then when I go to the next line, I have to scroll all the way to the left again, and then I have to scroll down to read the rest of it, and keep scrolling right, then left again, and so on.
However, this is another RFD of mine but it was uploaded to justpaste.it and then archived: http://archive.ph/VuDov
This time, I can read it nicely on the computer, and also zoom in or out when reading from my android. What's even better is that, when reading from justpaste.it using my android, even if I zoom in, the size of the text will automatically adjust so that it fills my whole screen, meaning I will never have to keep scrolling right left down right left down over and over again.
What makes justpaste.it better than the default voting tool, and better than Pastebin, is that, with justpaste.it you can change the size of your text, you can choose different colors of your text, you can make it bold, italic, or underline, and you can even insert images into it, none of which you can do with the default voting box or with Pastebin.
The site also has an option to purchase a "premium" to encrypt your text, but that's not necessary for writing RFD's. You can just write your RFD without having to worry about a character limit and post it. It also saves your progress so if you're writing a long RFD or something, you can write some of it now, then return and come back a few hours or days later to finish it before the voting period is over, whereas you can't really save your RFD in debateart's default voting box and come back later.
Then, if you want to preserve it, you finally archive it and then link to it when casting your vote in debates.