As you can see, this betting concept offers a way worse player edge compared to the main game. Still, they're famous for a few reasons.
First of all, side bets provide options. Betting on the banker's hand hours on end may be safe, but it can get boring really fast. Changing up your strategy and including them might as well add some tension back into the gameplay.
Second, if you love taking risks, this is an excellent strategy to try. You can see how small the chances of any side bet winning are, but acquiring a large payout can be an excellent motivator.
It adds to the enjoyment of the game. If you're playing not to win but for entertainment, you won't be too upset to have lost some money. Gambling is entertainment, much like going to the movies and hiking, and you need to ensure it stays that way. Surrendering to the moment can be the best outcome you seek, whether you win or lose.