Like others said, it depends -- if you have low latency streaming on as a streamer + low-latency viewing by the viewer + good enough internet, your "latency to broadcaster" can drop to 1 point something.
What you linked is streamers intentionally increasing their delay to account for stream sniping, but many streamers keep their delay not-extended to allow for better chat interaction. In some games, increasing delay to prevent sniping is just ineffective -- Valorant can regularly have 5+ minute queues in top ranks, and there's few enough players that even if you enter the queue very late, you can still run into them.
What you linked is streamers intentionally increasing their delay to account for stream sniping, but many streamers keep their delay not-extended to allow for better chat interaction. In some games, increasing delay to prevent sniping is just ineffective -- Valorant can regularly have 5+ minute queues in top ranks, and there's few enough players that even if you enter the queue very late, you can still run into them.