In Martin Goodman’s review of Raya and the Last Dragon at Animation Scoop, he makes the observation,

This movie is set in some mishmash of ancient East Asia and the time is not contemporary to ours (I didn’t see any modern architecture, weapons, iPhones, or any vehicles save for what looks to be a giant rolling pangolin), but too much of the dialogue is in 2021 lingo, lending a bizarre tonal contrast to the visuals. One of the worst offenders is Sisu; Awkwafina’s performance is truly fine, but her lines diminish the character; she might as well be playing herself. Maybe Disney does this to chum up to the older kids and tweens; I for one hate it.

A good point. Is it really worth spending so much time, money and effort to depict ancient civilizations to service the story, so audiences can lose themselves in this marvelous past, only to blow this illusion with hip dialog?

Bill Hunt of The Digital Bits notes,

When the film introduces its characters—and the terrific vocal talent here begins to establish itself—the story quickly picks up steam. Unfortunately, that momentum grinds to a halt again briefly when Sisu and Boun (the latter voiced by Izaac Wang) appear, because their dialogue is presented in a contemporary, improvisational style that feels completely out of place with the rest of the film. Clearly, the producers were trying to capture a bit of that old ‘Robin Williams in Aladdin’ magic, but that approach is very hit-or-miss.

The character of Raya, it seems, was influenced by Hayao Miyazaki’s Nausicaä of the Valley of the Wind. All right, let’s compare with Miyazaki’s oeuvre–Spirited Away, Laputa, Princess Mononoke, Howl’s Moving Castle. What’s the difference? No hipspeak.

Disney filmmakers may claim reverence for Miyazaki’s works, even superficially borrow some elements, but fail to apply his storytelling ethic.

Here’s an Honest Trailer that also references “2010s banter” (3:40):

Note the “timeless” dialog in the following clip:

“We were doing a jumpy thing.” “My bad.” “I get it, now.” “I’m with it.”