16% drop expected in roughly 11 days. That’s using the programmed algorithm designed to maintain block mining to an average of 10 minutes. Of which has slowed to more than 13.
But if you have something to disprove the programming, then please share. There are valid reasons for the difficulty change would go up so of you have anything that would disprove my belief, please share.
And on the front of centralisation, I would argue nodes have just as much power as miners. Nodes have in the past blocked blocks doing things that less than 51% support. In reality, we have a decentralised mining with distributed nodes. There are a number of pools that take the opinion of their distributed miners to set their support accordingly.
Bitcoin has better distribution compared to say Bitcoin cash which primarily is mined by one company that has a patent on the algorithm to mine.