See, all of those sound "derivative" to me. Absolutely nothing against Japanese yacht rock/soft funk, but it's silly to blame musicians for using genre conventions when those are inherently part of the musical language IMO. Particularly given Cindy Lee works with 1940s-60s pop genre conventions of girl groups and also performs in drag, it's inherently a kind of music that repurposes familiar elements to say something new.
I've been a fan of Cindy Lee's work since before they started the project and were in the band Women, who're a sort of your favourites' favourite artist. Part of the hype around Diamond Jubilee is the context of that band, and the development of successor bands since.
But part of the hype is also that it comes from a very sincere place - it's a full-on auteurist work, the antithesis of "lo fi chill hip hop beats to study/relax to". It can aesthetically or artistically be your thing or not (it very much is mine), but it's a breath of fresh air to have such a fully-realized artistic statement that isn't a focus-grouped, try-hard Event get the acclaim it deserves.