WLAN connection good or not?

Hello is that good to stream on twitch?

That's more than enough for Twitch.

Yes, but do you want to stream over your smartphone or over the PC?
More important than the question of how good the connection from your smartphone is, the question is how good the connection from your PC is.
That can deviate with W-Lan quite strongly if a device stands only 2m further somewhere else.

It makes you rich you just have to look how stable the whole thing is. Honestly, I do not know a streamer that streams with Wi-Fi and I'm on Twitch relatively often. For IRL streams, but not at home.

Small jerking annoys the audience quickly and you lose them, especially as a new streamers.