I’m really struggling with the premise of the question! It’s a good question, don’t get me wrong, and I’d love to jump in with examples. But the more I dive into it, the more it turns into soggy biscuits in my hands.
Despite the popular and compelling idea that he internet has opened up the music world to the point where anyone can have a hit, the resulting millions of releases every week have made it harder to break through the noise. So I don’t think it’s possible to have a popular hit without a sizeable investment in production and promotion.
If I was part of a production team with a good budget, and the song became a hit, then whatever I did in the mix wasn’t bad. Even if I made technical errors, like clipping inputs, mixing the bass wrong, audibly pumping the drums, leaving out of tune vocals on there - a number of things might happen.
If those errors mean it’s a genuinely bad mix that ruins the song, I’ll be fired and the act will go somewhere else to get a good mix.
If those errors are ignored and the song is released, it’s likely the mastering engineer will fix the worst of them - at the very least the ones that are a barrier to being able to listen to the mix at all.
At that point, if it’s released and flops, well it’s not a popular/ hit song and the question doesn’t apply.
If it’s released and is a massive hit… how can it be a bad mix? It can’t. Whatever you did is loved by millions. If it’s a hit, then whatever you might identify as a problem is just irrelevant to the appreciation of the art, or enhances it in ways you might not have predicted. And you’ll find copycat acts releasing songs that mimic those same mix errors.
The point being, to a certain extent, a hit song defines its own standards and criteria for success. That’s not to say that you’re not MUCH MUCH MUCH (as evidenced by the last 100 years) more likely to have a hit if you conform to genre standards… but however you get there, if your song is a hit it’s judged on its own merit.