Apart from whatever other hosters reaching top usage positions (like anonfiles, and gofile and pixeldrain and other semi-privacy-violating ones worryingly teetering around, along with expected heavy-hitters like MEGA and Mediafire and some well-known cloud-based solutions) due to getting recommended on Reddit and/or "hacker" 4chan every once in a while (alas, meaning having to prep for old-timers like 4shared going the dodo
); methinks decentralization could've also played a role - literally hundreds of open-source coded self-hosted instances of whatever flavours to choose from (semi-temporary hostings, privacy strengthening, advanced functions; anything goes),
like these examples for a start