Polkadot token holders have complete control over the protocol. All privileges, which on other platforms are exclusive to miners will be given to the Relay Chain participants (DOT holders), including managing exceptional events such as protocol upgrades and fixes.
Token holders keep the network secure and collect rewards by
staking DOT. Polkadot’s advanced staking system is designed for maximum decentralization and fair representation, rewarding good actors and punishing bad actors to ensure network security.
New parachains are added by bonding tokens. Outdated or non-useful parachains are removed by removing bonded tokens. This is a form of proof of stake.