Network-level metrics for Ethereum's mainnet entry and exit queues

• activation_estimate is the estimate time between deposit transaction broadcasted and validator active and earning rewards
• exit_estimate is the estimate time between exit broadcasted and validator out of active set and not earning rewards anymore
• withdrawal_estimate is the estimate time between validator exited and the ETH returned to the withdrawal address. There's a min and max because this is done in a round robin way so actual withdraw depends of validator position at the moment of exit