I can't speak to the quality of the M1 since I haven't used one yet, but I don't think the sales numbers mean that much. Basically just new shiny model outsells old standard model. Just look at the website. What would you rather buy, a standard model, or the one "supercharged by the Apple M1 chip?"
I assume Apple sells vastly more Airs and 13” Pros than they do any other machine they make. The lower price is a huge contributor. If the M1 were only on the top end machines, this thread wouldn’t exist.
OTOH, people who might have otherwise upgraded to one of those older and more expensive models are holding off on purchasing until new higher-end models are available.