The DNS equivalent technology there is DHT(distributed hash tables) [3] which was used in torrent technology for a few years. Ever wondered about how you can find the torrent seeders without a centralized entity? The Bittorrent DHT is the underlying tech.
[0] https://ipfs.io/
The Bittorrent DHT is not fully decentralized, it needs a list of hardcoded bootstrap nodes. https://stackoverflow.com/questions/1181301/how-does-a-dht-i...
Anyone can make an alternative client that uses the exactly same tech with different bootstrap nodes, and once they gain popularity, there will be people using that.
Democratic, I would say.
So in practice you can get peers from the list of previous peers, PEX (peer exchange), or a tracker for a given torrent.
So in practice once you talk to a few bittorrent peers (of millions) you likely are talking to another DHT peer and can bootstrap. Also given that there's typically millions of peers in the DHT, even brute forcing it by search IPv4 (4 billion addresses) for a few million peers is likely to only involve a few 1000 UDP packets or so.