I definitely prefer single bets. With multi bets, it can be very easy to be tricked into a false sense of confidence. Just because 5 individual events each have an overwhelming favourite, it doesn't mean that all 5 together are likely to happen.
Consider 5 events where a good team is playing a bad team. Each good team has a 90% chance of winning. You make a bet on one of these, you have 90% chance of winning. But make a multiple bet on all 5 big teams winning, and your odds are 0.9^5... which is only 59%.
The odds are even less than that, they are 45%.
But I'm sure it was a typo, and I get your point.
If you ask me, I think it's easier to win a single bet with 45% win chance than a multi-bet of 5 with the same cumulative win chance, although mathematically the chances are the same. So, I too prefer single bets. But sometimes, when I win 3 bets in a row in one day, I think, why didn't I placed them all together as a multi-bet to win several times more?
I mean, I wouldn't avoid multi all the time. Sometimes it can be fun.