Does google have a legal obligation to be fair or transparent? I thought what made google tick was the army of manual and arbitrary blacklisting where SEO cheat

Does google have a legal obligation to be fair or transparent? I thought what made google tick was the army of manual and arbitrary blacklisting where SEO cheating like e.g showing a full article to the google bot and a “subscribe to read the full article” to everyone else was way over the line that could lead to a ban