Linux has built countless cathedrals, but still no bazaar.
By that I mean every corporate cathedral you can shake a mouse at is full of Linux, yet Linux has not yet enabled a free and open marketplace for every business and every customer. Instead, every human being on the commercial net remains trapped in corporate cathedrals, many of which are ravenous for the blood of personal data, most of which is acquired by surveillance. In fact, nearly our entire existence in the commercial world is inside cathedrals where we have near-zero autonomy and great exposure to whatever those running the cathedrals wish to know about us.