Every TCG buyer I've spoken to is always "up" on cards, though if you dig further you'll find they haven't cashed in any actual gain and are just mentally up based on what they think they could sell them for. While also mentally discarding any losses.
The real winners are probably the people reselling the unopened packs for slightly higher than retail since they have removed the gambling aspect.
You can pretty much be guaranteed to break even if you check the odds of scratch tickets and buy enough of them. You can check how many tickets are left and which prizes are left for a particular game. That's what we did when I went in on a bunch of tickets with some friends.
Speaking of trading cards as a side hustle, a couple of my friends used to drive around the region buying boxes of baseball cards. They'd weigh them to figure out if some specific special cards was in it, return the light boxes, and throw out most of the other cards from the boxes they opened. Now that same card series has unopened boxes going for like $2k
The real winners are probably the people reselling the unopened packs for slightly higher than retail since they have removed the gambling aspect.