We need to take risks to win something, not only in gambling but in every aspect of our lives and the higher the risk ratio the higher the gain if the result is achieved successfully. To give an example specific to gambling, let's imagine that a popular football team competes with a lower league team in any event or cup match. In this case, since the winning rate of the popular and strong football team will be quite high, the winning rate of someone who bets with this option will also be low but the probability of winning for someone who bets by choosing the lower league team will be higher because the risk will be higher. In the shortest way possible, I can give an example of "the more bread, the more meatballs".
Yes, it is true that if we want to win something, we have to take risks to get it. We also need to realize that the higher the risk, the more likely we can win something, but that does not guarantee that we can get it because, in gambling, there is no certainty after playing gambling. In the example you gave, the popular soccer team will only sometimes be able to win if the underdog soccer team has something that can turn the direction of the match so that they can win the match. This has often happened to many teams, so we must understand that a match will have a surprise factor. If we want to avoid higher risks in gambling, we don't need to place bets with a lot of money and only use enough money so that if we lose, we won't lose quite a lot.
Risk is good as it is what can help you make more, for instance, today, I was unable to risk much and I gained so little despite being sure of the decisions I wanted to take. Had it been I took that risk, I would have gained about 9 times of what I made, but I never had the mind. So, the risk is good and no one can tell me otherwise, only that we should take only the reasonable risk so that it will not be an issue for us over time. The best is to keep the right account management when we are afraid, this also helps, because most times, even if the risk is worth it and we are so afraid due to one reason or the other, we can rely on the right management. With this, after all, we might lose, but it will not let us lose too much to the extent that it will affect our psychology.
But it is not as easy as we think too and I wouldn't blame those who are not able to risk high due to fear and too much conservativeness. The reason is that some people have risked high and lost high as well, to the extent that it badly affected them. But some people have not risked at all and they remain in their situation without any tangible achievement, unlike those who are risk-takers that eventually make it big. This makes the situation uneven as it is not always the same with everybody. In all, we should have that mind of risk, I think it's best if we want to move higher, but such risk that we take must be reasonable and must have been premeditated, and calculative at the same time, not that we will just be taking the risk senselessly and without proper account management in consideration as many do but will come back to regret and even blame other people at times.
However, about the underdog example, I dare not, unless I am sure of the underdog. Just like what Girona is doing in Laliga this season, I can bet on them for good.