On the contrary, roles are becoming native. That is, checkboxes have always been checkboxes but now with an actual default "checkbox" role! But haha, the roles are still being rolled out, so to speak.
At least some browsers have been able to pass these roles on to AT, which is how we know NVDA had that bug where a nav element with an author-added role of "navigation" tacked on actually announced two navigation roles! It was able to read the one from the plain nav tag.
@ wollen muts lekker warm! But so itchy!
Bruce Lawson likes to call "main" a "Scooby Do" problem. In Scooby Do, the person who was the monster or ghost was any character in the show who wasn't one of the Gang. To determine if your box makes sense as "main", just check off that it's not:
(main chunks of a page)
Whoever's left, is going to be main. And yeah, even if there are a bunch of separate articles in that box, I think main can be a good role for whatever's wrapping those articles, if it's the main content of that page. You'll have just one main role per page, and it doesn't really matter if inside the articles are more headers and footers and comments and whatnot.