The job being monotonous is clearly enough of a downside that significantly higher pay and benefits are needed to attract talent.
Paying higher wages might help retain employees (or not! there are jobs people just won’t keep doing no matter the pay) but doing so could easily increase costs to the point where your product is uncompetitive in the market. It also might just be worth having higher turnover in order to keep prices low.
Except you can't just zone away in a factory job. Workers need to pay attention if they don't like injuries. It the job doesn't need much skill, it doesn't necessarily mean it's easy or safe.
We need actual data to decide how significant is "significant." Otherwise you will just have businesses complaining no one wants to work for "significantly" higher pay (a whole $0.05/hour more).
Obviously there is some ludicrous threshold of pay where more people will decide to do some job. But for practical purposes the pay needs to be in line with still being able to price your products competitively in a global marketplace.
Even $10,000/yr more might not be enough to move the needle all that much on a job that’s backbreaking, monotonous, and with little prospects for career growth. Especially if you have a limited pool of applicants due to your location.
Theoretically, an utterly horrible job with great pay would attract a lot of workers who do it for some time to get a financial boost before moving on.
A lot of folks like repeatable, monotonous jobs. They can loose themselves in a trance doing the same thing for hours.
The problem is that American bosses will never hire these kind of people. They can never pass the interview game.