I've met a couple teens who, for Discord on mobile, have the hilarious workaround of just leaving screen recording running 24/7. This obviously gives you a complete log of every pixel you see, at the cost of having to go in and manually delete the files fairly often.

Somewhat relatedly, the Tweetdeck client for Twitter appears to be write-only, because I'll routinely see two or three instances of the same tweet where the author deleted to fix a typo, and other more embarrassing tweets, including at least one that was obviously meant to be a DM.