The Panel

Hirokazu Kore-eda won the Palme d'Or at the Cannes Film Festival in 2018. The Palme d'Or is the highest prize at Cannes, which is considered, by a specific and influential type of person, to be the highest prize in cinema. That type of person has expectations.
He has made a documentary about Ultraman.
(Ultraman is a Japanese television franchise that began in 1966, in which a giant alien from Nebula M78 merges with a human scientist and then, when necessary, grows to approximately forty meters tall to fight other large things. The franchise has been running for sixty years. There are currently multiple ongoing series. The merging-with-scientists question has been revisited many times. The franchise has never fully resolved it. I am not making this up.)
The documentary is called "The Origin of Ultraman." To help explain the origin, Kore-eda assembled a panel of experts. The experts include Guillermo del Toro, who has won two Academy Awards and also directed a film in which giant robots fight giant sea monsters for humanity's survival; Hideo Kojima, who makes video games of such narrative complexity that for several years the discourse was whether they were good or simply very long; Hideaki Anno, who created Neon Genesis Evangelion, a 1995 animated series about giant robots that became an extended conversation about whether the robots or the people piloting them were the real problem; and Shinji Higuchi, who has spent his career making giant things look real enough to be frightening.
(The intersection of Palme d'Or winners and people with documented strong opinions about Japanese giant-man television franchises turns out to be non-empty.)
This is not, as it happens, an unusual gathering. Anno himself directed Shin Ultraman in 2022, which was released in Japan as a theatrical film and reviewed as such. The critical process was not complicated by the fact that the film involves a man who grows to forty meters tall when the situation requires it. Del Toro has spoken at length about his love of kaiju and tokusatsu. Kojima has said things about the emotional weight of science fiction that would be at home in a graduate seminar. None of them seem embarrassed about any of this.
What the documentary appears to be documenting is: what happened to the children who watched the 1966 television show and then became, separately, Guillermo del Toro.
The answer, based on the available evidence, is that they won awards and then kept caring about the thing they cared about before the awards. The Palme d'Or is an excellent prize. It does not change what you loved when you were seven. Based on the documentary that exists, someone in that room loved Ultraman at seven. Probably several of them. The documentary will be available at a later date.
The Cannes Film Festival has not indicated whether it plans to screen "The Origin of Ultraman" in competition. I assume they are discussing it. I also assume it would win.