Your experienced, your opinion, and for sure there are different opinion with gambler who manage to work out with combo/parlay types of betting strategy, I don't have any argument or much better to say that I believe that your personal experience dictates that for you it's better to use a single bet and risk your money compared to a value bet that for me most of the time can ruin your bet.
A single mistake will cause you to lose your pick, but same deal with a single bet if shit happen it will be still the same outcome to you.
I've also done combo or parlay bets in sports betting but it only makes me lose more money.
I will not repeat this mistake even though it has a higher percentage of profits than a single bet but instead loses money even bigger than a single bet.
For those gamblers who can take advantage of combo or parlay bets, maybe they will continue to bet, but it seems difficult to be able to do research or predictions when betting using this method.
I wasn't disappointed, it's just that this experience taught me a lesson that I have to be able to bet well and choose which ones can really give me an advantage.
The sole purpose of taking the parlay is to make your winning much larger, compare to single bet especially those bet for heavy favorite, the odd is small so gambler who have high confidence with their knowledge pick parlay or combo betting to make it better if luck permits them to win all the games that they've selected.
But like what all of us understand, just a single game that loss the whole parlay will lose together placing your bet at total risk.