@Gargron If applied as it is on birdsite, I find it makes following conversations much more difficult as it severely messes with threading. So unless you're willing to dig back into the history, post-by-post, it's easier to simply take the person's word that they're not taking things out of context.
So both from a useability and toxicity point of view, quote-toots would be a bad idea unless done in a dramatically different way.