If you still think that #TrendingHashtags were the ONLY reason to #ForkOffTogether, I highly recommend you read this medium article, if you are willing to have your mind changed:
"Two months ago it was a “people you might like to follow” feature, before that it was whether CWs should hide sensitive content when a post is embedded elsewhere on the internet, and in the past couple of days it was a “trending tags” feature."
https://medium.com/@cassolotl/i-left-mastodon-yesterday-4c5796b0f548