To start, decentralization is a direction in my view, not a destination. Are we heading in the direction of being more decentralized is the question? We have a distribution mechanism that allows for people to enhance their holdings.
As for the top 20, that can be done rather easily. A lot of HIVE on the open market. People simply need to buy and power up. Not a sexy answer but that is how it can be altered.
Of course, under an attack, there is always the fork option.
That is assuredly the real (and most important) question.
Sorry (not sorry) but I tossed my rose tinted glasses and kid gloves out at the turn of the new year. Which is to say that I am exerting maximum candor.
I want to see Hive persevere and be... not only what it can be but what it is supposed to be.