Friendica (formerly Friendika, originally Mistpark) is an open, free, distributed social network. It forms one part of the Fediverse, an interconnected and decentralized network of independently operated servers.
I just registered an account and it seems to me that friendica is trade-free. However the browser extensions Privacy Badger and uBlock Origin go a bit crazy, but that must be because of the content and the external links posted in the feed. I also found out with uBlock Origin, that friendica uses Matamo which is a powerful web analytics platform.