I'm a huge fan of the multi bet. Especially if you closely follow a sport. I feel like I can hit a 5 game parlay with much better than the odds presented based on how much information I consume regarding NBA basketball. I frequently make tiny bets, and while most of them are in fact losers, I win with a much higher % than the odds I am given. 1 large parlay can make up for weeks of losses with a very small bet. Everything to me is risk reward. I don't want to take a risk to double my money, I want to take a risk to 50x my money. If it's an educated risk, all the better.
I suppose this is a central point in this discussion here: In a multibet you can bet with smaller amounts of money and still get huge gains. The fee might be higher but you also leverage your money in a sense. So for the occasional bet with small money a multibet is very attractive. It is a different story if you want to place large bets, then fees become more important and often large bets are for a single event only