Copying from Reddit because they don't allow people to read posts when not logged in:

You open a booster, shuffle the cards, and place them face down. You then have two people that alternate between flipping it (pick a card, flip it up and they get to keep it) and ripping it (ripping the card in half then at the end revealing all the cards that have been ripped).

There are people within the community that get annoyed at people playing this, as it's seen as a sign of privilege and disrespect, like recording yourself burning money. The person playing it is showing that they don't care if they get a valuable card ripped in half, I think it's pretty stupid personally, but it's their possession to waste if they want.

I think this is stupid, but I also think NFTs / TCGs are stupid. The money was wasted when they bought the cards. Ripping Magic cards is like right clicking NFTs to me, so this is cool

Oh, here is a 7 year old Reddit post explaining the "flip it or rip it" phenomenon

Dumb! Idk anything abt MTG, I just hate waste and pointless destruction. But on the other hand, it's just a piece of paper. Sigh. I guess they succeeded in triggering people...