To answer your question, my personal thought on this matter is based on my understanding of the FAQ on the EOS.IO website.
I understand from the FAQ that there is a bit of centralization in the EOS.IO system otherwise any EOS Platform that adopts the EOS.IO Software will not require the approval of holders of not less than 15% of the total issued.
Technically, the 21 mining nodes will be "centralized" (in 21 different locations around the world) as well the IPFS servers. This hi speed of transactions per minute and this amazing scalability requires a great use of RAM memory, this RAM will be part of the running nodes.
WE, the tokens holders will elect the miners and any other candidates who would like to assume some responsibilities for the community.
Here Is an EOS-miner candidate who introduced himself on steemit a couple of days ago.
I am going to vote for him : Eric from Sweden