Gaming PCs will be fanless sooner than expected. According to Prime Computer, the potential is here :
"Conventional online gaming has been there for a long time, but the future is game streaming. Players only streams the video, while the demanding computing power is delivered by a cloud data center. The passively-cooled, silent, and compact PrimeMini 4 meets these requirements.
Some game streaming platforms are already on the market. But cloud gaming will take off when the big cloud providers, such as Microsoft or Google, join the party. Google's game-streaming platform "Stadia" will start at the end of 2019. The only necessary software for Google "Stadia" is the Chrome browser."