@Sasha Lomas actually, every platform uses some kind of algorithm to control who sees the posts -- otherwise, spammers would take control.  Or, the least interesting posts would compete with the most interesting posts (to the reader's eye). The algorithm is based on the relationship between each reader and each publisher/creator: it notices the reader's behavior (whether they read/watch a piece of content) and will adjust accordingly whether that publisher's future content is more or less visible to the reader.

Facebook has the most experience tuning its algorithms to be more "interesting" (truthfully: addictive) to most readers/viewers, hence its growth. 

If you find another platform that helps you reach the people you want to reach, while having your content be more visible to them (compared to Facebook), of course that would be worth exploring.  I'm always curious what social media platforms people prefer.