In February 2020 Parasite became the first film not in English to win Best Picture, and the first film ever to win both that and the Palme d'Or.
What actually changed
Subtitled films did not suddenly become mainstream in the United States. What changed was distribution: streaming services began commissioning and promoting non-English originals at scale, and the assumption that a subtitled film needed an English-language remake weakened considerably.
What did not
The Academy's voting body remains the same body. No film not in English has repeated the win since, and the international feature category still exists as a separate track, which is the structural problem the win was supposed to have solved.
The film itself
It holds up. The vertical staging — every relationship in the film is above or below another one — is the kind of formal idea that survives repeat viewing, and the tonal hinge at the midpoint is still startling when you know it is coming.