$(".chat-container").remove();
$(".chat-container").remove();
And if you for some reason want to participate in chat, there is irc.twitch.tv, where you can simply join channel #streamname in IRC client of your choice, again without all the web crap, and without all the inane twitch emotes.
I've been doing that for a few years now, much more pleasant experience than their web interface.
You can close the chat window if you want, but I'm normally watching things where the streamer is engaged with the chat and volume is fairly low.
I will say, in the circles I move in, many content creators are also running a discord along side twitch. Some will even invite people into their voice chat to talk with them on stream.
I much prefer using discord in those situations, but that may be partly due to the higher barrier to participation that using discord immediately entails.