I can totally understand how being able to say one is a bestselling author would certainly be a big thrill. And while it's true that the 10-book-set at 0.99 approach is an artificial situation, if I recall correctly, some people made the list with a single book--probably at 0.99, and probably marketed the hell out of, but still, I get why people wouldn't want to lose that.
How much such a designation really affects sales going forward is another thing. Is Stephen King popular because he's on the bestseller list, or is he on the bestseller list because he's popular? I think it's more the latter than the former. A previous unknown who made a list would probably get a boost from that, though it depends on which list. NYT has all kinds of genre sublists, or at least, it used to. I know someone who was around #15 on one of those, so he can claim to be an NYT bestselling author, but it didn't really do much for his sales. From what I recall, the people I'm aware of who made the USA Today list were pretty big sellers before and pretty big sellers after. I don't recalling any of them saying that making the list was a game changer for them.
I'm not sure whether the general public pays attention, but Amazon Charts is still going, with lists for both fiction and nonfiction, most read and most sold. Most of the top twenty each week in each category are big-name authors that you'd recognize immediately, though there's usually at least one Amazon imprint book (though not this week), and sometimes, there's an indie book. This week, it's Zodiac Academy: Sorrow and Starlight, the eighth book in what I gather is a popular series. (The book is $8.99, with both kindle and paperback editions, but no audiobook, so it's working at somewhat of a disadvantage. But it's #1 in two of the three subgenres mentioned and 2 in the other, and it has over 4,500 reviews. Even at that, it's only #18 on on most read, so that gives you an idea of what your sales volume would have to be like to hit #1.)
Oh, by the way, the most bought fiction list also has an indie this week (at #10). (There is a publisher listed, but it has the same name as the author, so self-published.) There's also a book from Montlake (Amazon imprint) and one from Amazon Original Stories there. Oops, and there's another indie at #14.
Since Amazon Charts is undoubtedly put together by algorithm, I think it's here to stay. I don't know how much it's viewed, but it is a list indies can make. And Kindle Select books, which wouldn't qualify for most lists because all the sales would be Amazon, are eligible for Amazon Charts. In fact, they have an advantage, since KU stats are included, particularly for most read categories.
I don't know if that's a comfort to anyone or not, but I mention it for what it's worth. It's certainly a list that has indies far more often than any other.