I look at Medium as fundamentally a subscription service that happens to be accessible by Google. The Prags are a big upgrade for anyone interested in programming and it's a lot to include in a $5/month service. If Google and social media links only send you to Medium 1 or 2 times a month then it might not yet be a subscription for you. (Yet, because this isn't the last upgrade). It's not fundamentally anyone's goal to put the Prag books online for free (AFAIK). Those books took a lot of author time to write and a lot of paid work to edit and produce. And without the financial piece, I don't think these books would exist, let alone be online.