In theory, I agree with you...though I can't really come up with many examples of people I'd have nominated who'd fit the "more populist than serious, still deserving" criteria. I do think there's always been a tendency among Oscar voters to conflate "solemn" with "serious", and performances like, say, Fiennes in Grand Budapest Hotel, or Hugh Grant in Four Weddings and a Funeral, have been overlooked for less impressive work.
I will, though, confess to an aging-guy worry: I've watched critical reaction change over the past few years. It seems to me we've seen a generation (if not generations) of critics move into place who've never known a time when serious movies were also popular movies (which was the norm well into my adulthood). Because, in their experience, most any movie with ambition has been a late-Fall release geared to an awards campaign, they tend to lump all of them -- from a dull biopic like The Theory of Everything to a PTA masterpiece like Phantom Thread -- as "Oscar bait," something to be mildly disdained. Conversely, they seem to elevate (I'd say overrate) genre pieces like the ones that have been their daily bread since childhood -- super-hero movies (the Dark Knight and Black Panther pushes), horror films (Get Out their big success, but also advocacy for things like Hereditary), pure action (hello, Mad Max: Fury Road) and broad comedies (Tiffany Haddish, Downey Jr. in Tropic Thunder). None of these genres strike me as generally prize-rating -- The Dark Knight and Get Out are the films that come closest for me, and I'm 50/50 on either -- but I think we're heading to a future where more and more such films get promoted into prime Oscar position, because critics, who used to dismiss such films, are now promoting them past their station.
I'm actually not sure if any of this applies to Hustlers, which may be able to pass for a serious movie on a female empowerment/critique the rich basis (though I'm thinking, commercially, it's going to ride somewhat on "watch half-naked women work the pole"). But the certain JLo campaign seems guaranteed to draw out the worst of junk-movie-loving Twitter.