One reason for the change in costumes could be that Fantastic Beasts is mainly set in America and their wizarding fashion in the 1920s might have been aimed at blending in with Muggles (or No-Majs) out of fear of being found out. American wizards seem to blend in with Muggles more than English wizards.
Why do they wear muggle clothes in Fantastic Beasts?
Why did Dumbledore wear muggle clothes in the Fantastic Beast series? - Quora. The costume designers did this intentionally as they wanted Dumbledore to seem like a young, refreshing, and cool professor that students would feel comfortable talking to and becoming close with.
If you are thinking about the books then it's because Dumbledore's got style. If you are thinking about the films then it id because the production design team at Warner Brothers decided the wizards should dress more like Muggles after the third film in the series.
Students might wear their muggle clothing underneath when they are getting off of the train, for changing convenience, or maybe when it's a bit colder. But on normal school days, it is likely that students only wear Hogwarts robes.
He was a powerful dark wizard who dreamed of a world where wizards ruled over Muggles. Grindelwald was obsessed with the Deathly Hallows and even embarked on an expedition to find them. His journey led him to Godric's Hollow, where he developed a romantic relationship with Albus Dumbledore.
Fantastic Beasts: The Secrets of Dumbledore | A Muggle Thing | Warner Bros. Entertainment
Was Dumbledore a pureblood?
An interesting fact of note is that despite the ideals that pure-bloods are inherently more powerful wizards, some of the most powerful or particularly adept wizards and witches in the series are in fact either half-blood (such as Lord Voldemort, Albus Dumbledore, Minerva McGonagall, Severus Snape and Harry Potter) or ...
Gellert Grindelwald (1883-1998) was considered to be one of the most powerful Dark Wizards of all time, second only to Tom Marvolo Riddle, who later became known as Lord Voldemort. He was schooled at Durmstrang Institute until his expulsion.
Diagon Alley is a high street located in London. It is accessible to the wizarding world, to which it is something of an economic hub, but hidden from Muggles (non-magical people). However, Muggles are allowed access to it if they need to accompany their Muggle-born magical children.
Why do they wear Muggle clothes in Prisoner of Azkaban?
But in 2004's Harry Potter and the Prisoner of Azkaban, the students hardly ever wear their robes outside of the classroom. That's because costume designer Jany Temime, who worked on the last six films, had a different vision for the kids when she was brought on to the project.
This potential often surfaced many generations later. In Britain, these Muggle-born wizards and witches would often join the wizarding world when they were invited to attend Hogwarts School of Witchcraft and Wizardry.
Without her knowing, three Muggle boys had been spying on her. After becoming scared of what they witnessed, they confronted her. The boys tried to get Ariana to show them her trick, but when she was unable to because of her young age, they turned violent and started to attack her to stop her from using magic.
While the act did destroy the ring as one of Riddle's Horcruxes, it did not stop the fatal curse. The curse gave Dumbledore's hand a withered black look, as though it had died. Severus Snape managed to stop the curse in his right hand, but warned him that he had only a year to live.
The concept of wizards ruling over muggles was the two men's initial goal, and they made a vow at a young age to keep this philosophy as the driving force for their actions together. But Dumbledore came to appreciate and respect muggles, so he eventually abandoned the cause.
Why does Dumbledore not wear robes in Fantastic Beasts?
Another reason could just be because Fantastic Beasts wanted to mix up the Wizarding World a bit and go for a new look, as wizards wear a mix of Muggle clothing and robes in the Harry Potter movies while Fantastic Beasts decided to go for all Muggle clothing.
Hermione was raised the only daughter of two Muggle dentists, Dan and Emma Granger, making her letter from Hogwarts her first form of contact with the Wizarding world.
Why don't the wizards wear robes in Fantastic Beasts?
In “Fantastic Beasts,” wearing a robe in New York City doesn't work. The wizards are trying to hide among Muggles. Elsewhere I've posted that robes would be physically dangerous in the crowded city, as they'd be sat on, stepped on, gotten caught in doors and gears and doorways.
Those who could not prove that they had magical heritage — in other words, any Muggle-born and potentially some half-bloods — were sentenced to Azkaban for having "stolen" magic. Some, however, were apparently released after being stripped of their wands and their jobs, and ended up homeless.
Even Muggles feel their presence, though they can't see them. Get too near a Dementor and every good feeling, every happy memory will be sucked out of you. If it can, the Dementor will feed on you long enough to reduce you to something like itself...
Slytherin disliked taking students from families with only Muggles, seeing them as untrustworthy and unworthy of being taught how to use their magic, and tried to persuade the other founders to only take students from pure-blood or half-blood families.
After the conclusion of the Second Wizarding War, Hermione sought out her parents and returned their memories. They presumably then returned to England.
How is Hermione a witch if her parents are Muggles?
Muggle-born is the term given to a witch or wizard who is born to two non-magical parents. Their magical abilities do not seem to be at all affected by their Muggle parentage — in fact, many Muggle-borns have been among the most powerful witches and wizards of their time, such as Lily Evans and Hermione Granger.
If, by unfortunate means, Muggles do happen to observe the working of magic, the Ministry of Magic sends Obliviators to cast Memory Charms upon them, causing them to forget the event. Some Muggles are aware of the wizarding world.
At some time after the end of the Global Wizarding War, Newt and Tina marry. Newt creates the Werewolf Register and the Ban on Experimental Breeding. Newt also works for the Dragon Research and Restraint Bureau. In 1979, he is awarded The Order of Merlin - Second Class for his services to magizoology.
In the end, Voldemort kills Grindelwald via Avada Kedavra after deciding he doesn't need Grindelwald alive anymore. The movie however, took a very different approach. After getting inside Grindelwald's cell, Grindelwald straight up tells Voldemort that the Elder Wand was buried with Dumbledore.
