Some here are getting it all wrong.
Reference to Stereophile April 2022: "Class ratings are based on performance...[including performance on the test bench]."
Nowhere is it suggested price or value for money have any relevance.
This irrelevance of price in determining Class is why the $$$ symbol is employed to highlight products that strongly outperform at their price point.
That's all.
So, to move to OP's point. Products in Class A obviously do not all have exactly the same level of sound quality. There is a range. Some just scrape in. Others are state of the art. So you do not just buy the cheapest one and expect the performance to be as good as the most expensive.
Stereophile publishes two pages of explanation of the ratings. It does pay to read them.
I cannot write about Stereophile without including high praise for John Atkinson, possibly the best hi-fi journalist of the last 50 years (about the time he has been working). He holds very balanced, sensible, well thought out views on all the controversies and is thus to be trusted. He is a listener and a techie. Indeed, and a musician. And a recordist. I have been reading him since he started in the 1970s in UK's Hi-Fi News and Record Review.