There is a theory I heared in presentation of Joshua Cooper Ramo at the Blockchain Valley Conference in Switzerland, Zuerich that things start decentralized but than tend to centralizes automatically in certain "cluster" nodes. The example he brought was the internet. It started decentralized but today the internet seems to be google, amazon, facebook & co. So not so decentralized as you might think.

I wonder if we will experience something similar regarding blockchains.