There's also the issue that whatwg pretty much stopped adding new semantic elements; if I'm not mistaken, only <search> and <dialog> were added in the last decade, after the introduction of HTML5. <main>, <section> and <article> are increasingly being overloaded to the point of meaninglessness.

The most cited example of one that's clearly missing is <comment> for user-added content, but there are probably dozens we could add that could help deal with the div soup. By not adding any new elements, whatwg is essentially saying "You're not going to be able to use these the existing tags to fully add proper semantics anyway, so why try?"