If I had to guess, I would say the Japanese culture towards football is very different from what we see in countries that are considered to be the best ones and with the best performances. In Latin America, the football is a passion which starts at a very young age, here you can see children and teens not only watching the matches and following their favorite teams, but also partaking in their own matches, practicing during years and years, not matter whether they come from a middle-class family or a low-class family, they all do it and their training can be intensive.
Those who become professionals are generally the best of the best.
in Japan, I doubt it is like here. So the career path in that country does not pick the best talents among the people.
Japan, just like China, gives equal importance to Olympic sports. They are really good in Olympics, martial arts (esp. Judo) and wrestling. During the last Olympics (2021 Tokyo), Japan was 3rd in terms of medal tally and won a total of 58 medals including 27 golds. But when it comes to football, Asian teams in general are weak. But at least in case of Japan, we can say that they are a lot better than some of the more populous nations such as China, India and Indonesia. Only issue is that their quality has remained stagnant for sometime now.
Very true but to a certain degree it is also dependent on the geographic conditions of a country. That doesn't apply to most indoor sports, except for hockey, which is a good example for being a favorite sport in countries where there are mostly cold temperatures. The United States is a bit of an outlier.
In soccer it's not surprising that it is the most favorite sport where the weather is mediterranean. That was the case for a very long time as temperature does play a big role when it comes to sports and whether they can be played in a location or not. Only due to advanced technology in stadium construction it is now possible that you could have soccer in extremely warm areas as we have seen with the last World Cup.
The upcoming World Cup takes place in great locations. It is not necessarily mediterranean weather there, but it is also not hot like in the desert. It's going to be an enjoyable event for everyone. Countdown is running, only 3.5 years to go!