Increasing the failure threshold in YugabyteDB allows for more time to be given to a node to come back online, reducing downtime and improving high availability. The default threshold is set at 15 minutes, but this can be adjusted to accommodate environments with large data densities or other specific requirements. This involves changing two settings: follower_unavailable_considered_failed_sec and log_min_seconds_to_retain, which need to be set to the same value to achieve the desired outcome. With careful consideration of potential risks and monitoring disk utilization, increasing the threshold can provide significant benefits in terms of reducing downtime and improving overall system resilience.