Research cannot help you win, it can help you take the right steps and increase your chances of winning. For example, you are a football expert and you have been researching football for many years. Can you tell me who will win the match between Real Madrid and Atletico Madrid? Or who will win the match between Barcelona and Leganes?
You might say in the first question that the match will be competitive, both teams are favourites to win. But in the second question, you would definitely say that Barcelona will win the match. But Barcelona lost to them in a La Liga match. Here your research is completely useless and the outcome of the match depends on luck. So research cannot guarantee you to win the bet but it can increase your chances of winning a little.
You have chosen an example of a match in which there was a sensational defeat, which did not correspond to the game at all, of course this sometimes happens, but this does not mean that we no longer need to analyze matches before betting, because Barcelona lost one match to an underdog. There are many other matches (and there are many more) in which Barcelona wins and it is the favorite in these matches, so maybe in this case it is better to take these matches as an example?