(It is unfortunate that I can’t edit the reply relationship of my message, neither can I repost it as a good relation after deleting the earlier comment like how most messaging apps and forums work)
Facebook, YouTube, WhatsApp, Istagram, TikTok, WeChat, Telegram, Douyin, Snapchat, Kuaishou, Twitter, Sina Weibo, QQ and Pinterest are neither self-hostable, nor FOSS, let alone all the unethical practices of their owners. A detailed critique of just one of them would take hundreds of pages already.
Providing ethical alternatives to serve just a small fraction of use cases would be doing a great deed to humanity.