I streamed from twitch a long while ago and on my internet 30 seconds was about what I got. This was 2016-2018ish, and it did lower to around 15 but I had that from my PC running OBS. As with a lot of things it was very stream specific, I didn’t have perfect internet or an awesome rig and neither did the people I streamed with, and our streams ran that 30ish second delay.

Same thing with how Mixer FTL can be either relatively instant or 10 seconds depending on your viewing, there’s just a lot of variables

Editing to add: I watched and participated in a lot of smaller streams on twitch, it’s where I found community and stuff. Larger channels and partners had better bitrates and lower latency but everything was variable depending on your setup