How do people cheat on quiz planet, because they go from a very poor player..

To answer your question, people make use of another phone whilst playing, therefore when the questions come up, they use google voice assistant for quick answers.

You get Bonus points for each friend you get to join

I don’t know that people are cheating on the quiz planet. I got much better just by playing so long and so much,I finally started learning the answers. Sometimes I have a great winning streak and sometimes I do terrible but I still get better all the time.

For tournaments / group games, they set up multiple user ids, use one or more of those fake user ids to gather all the correct answers, then use their own primary id to enter all of the correct answers.
It's very hard to see what satisfaction they gain, since it is something a bright six-year-old could achieve, but still they do.
In my circle, unfortunately, there is such a cheat who posts a perfect 21/21 score on EVERY group game he enters, even when some of the answers are totally obscure.
Thereby spoiling all of the group games for everyone else, since we know, when playing the game, that the outcome is rigged.