It is really difficult to correctly predict the combo bets because here you need to predict few bets correctly in order to win the money. Even if you lost one bet, you will lose the combo bet. So it is really risky to go for combo bets.
The only reason why people will try their luck on these bets is that if they win these combo bets, the reward will be much higher as compared to win a single bet.
If you ask me, i will prefer to win a single bet even though my profit ratio will be less but it is better to avoid the loss by not playing the combo bets.
That's why it has better pay offs when you win. Higher the risk, higher the reward, it's based just on math. When you try to catch on easier bets you will have lower reward ratio.
Both of the styles can equally make you ton of money and both can make you rekt. There's no right or wrong way to gamble, there are just personal preferences.