Are they any better in 2019? Last I checked the anything beyond desktop compositing features is still a tyre fire of lying capabilities, broken functionality and wishful thinking. nVidia being by far the most stable while lacking integration with modern Linux APIs.
As a full-time linux user and occasional gamer, I have been using the AMD open drivers since circa 2010. The improvements have been massive, both in stability and performance. Since the availability of steam, I have been doing all my gaming exclusively on linux, logging a probably unhealthy number of hours on various games (Dota, various iterations of Civilization, City Skylines, Stellaris, etc.).
Not to say the situation is perfect by any means, but the difference from 2012/2014 is night and day.
Not to say they don't still have issues, but the linux gpu driver situation is vastly better than it was in 2012. AMD drivers especially has improved massively since then.