This is due to the fact that we won't be able to analyze all the games carefully that are in our ticket and won't have the advantage needed to win. So instead, it's recommended that we should value quality over quantity if we want to succeed in sports betting.
Yes, I agree with what you said here. We tend to overanalyze when we bet too much, and with that, we tend to lose if we are not sure about our bet. Also, I just want to add that if we bet too much, then we tend to bet too much money as well. What if those bets lose at the same time? Then you lost a lot of money. So I think betting on fewer picks is much better.
Also, single betting is much better than parlay betting because in a single bet, the chances are 50/50, 50% of winning and 50% of losing. So for me, it is much more advisable to bet fewer single bets. If you can bet one single bet per day, then it is much better because if you win, which is good, but if not, then it is fine because you just bet once a day.