I think the accurate statement of your opinion is not "the web is centralized" but rather, "Zipf's law sucks."
In decentralized networks there end up being accumulation points, and Zipf's law (which shows up in piles of different contexts, originally noticed in rank of words used in languages) gives a pretty good idea of how that accumulation plays out in basically an L-shaped curve. Point being that it might have a lot more to do with the structure of human networks and attention than with choice of wire protocols...
In decentralized networks there end up being accumulation points, and Zipf's law (which shows up in piles of different contexts, originally noticed in rank of words used in languages) gives a pretty good idea of how that accumulation plays out in basically an L-shaped curve. Point being that it might have a lot more to do with the structure of human networks and attention than with choice of wire protocols...