First person: Talking about oneself. I, me. Second person: talking about the listener. you, your. Third person: talking about someone who is not the speaker or listener. He/she/it/they Fourth person: Talking about total bullshit.

In this context, "Chat" is second-person plural, used by streamers to address the portion of their audience able to respond in the text chat that always accompanies these things. It does contrast with how a radio personality might address "listeners" because radio listeners don't usually have a method to respond in real time, so it's usually a rhetorical question; a streamer addressing the chat is asking for a response.

There are languages with a 4th person pronoun. The 3rd person is kind of the main character and the 4th someone else. That helps to disambiguate sentences like "The criminal shot the cop and drove away on his (own or the cop's) bike".

Or the "gay fanfiction problem": "He looked at him and lay his hands on his lap". Is it a happy ending or a sad one? That's one theory why gender in pronouns is so resilient: more often than not, the gendered pronoun can disambiguate which person is talked about. It doesn't always work, a 3rd/4rd person distinction is superior.

Why isn't that just 2nd person plural, like "y'all"?

Is it really that different than saying "Audience"? Or radio shows referring to "listeners"? Etc.

it's definitely 2nd person collective in its original usage and outside of its original usage it's not a pronoun because it doesn't replace a noun.

First person = someone describing their own point of view (ex: I, me)

Second person = someone being addressed (ex: you, y'all)

Third person = someone talking about someone else (ex: they, them)

Fourth person = the point of view of a collective group (ex: we, us)

I usually say "smash that like button" but ill throw in "chat" in the future to stay relevant with these kids.

Smash that like button if you agree with me chat

It's just a pronoun to address the Collective

It’s not even a pronoun in this context, it’s just a noun.

Is this the uncanny valley of dril tweets? I have no idea what this means

My pronouns are Chat/Commentor

me when i've taken half a class of english: bro chat is 4th person 🤓

"Everyone"?

I'll need to see some solid evidence and proof of this being done unironically before believing this.