I think they are real people, competent singers and players. English, I'd say, from their accents - they don't appear to me to be miming.
Her lip-gloss and earrings may be to appeal to the advert's target demographic!

Or maybe AI videos are better than I think they are.

The lyric "Way to go!" is amusingly double-edged. I doubt it that phrase was written by AI. Somebody in an ad agency perhaps.