I'm not sure what the implication here is - that wealthy people can afford better healthcare? Or that wealthy people have superior biology that allows them to ignore the chemical effects of ethanol?
If the former, what kind of healthcare are wealthy people getting that nullifies the effects of ethanol?
They may have a 6-figure job, where the boss doesn't care if they come in late or hung over, or even drink on the job. They may live in a nice condo nearby, and walk or bus to work. They can dress nicely and go out to nicer places, and not get asked to leave for being a little rambunctious.
I've known many people who fit this description.
A person with a minimum wage job who drinks the same amount is spending a much more significant fraction of their income on alcohol. They have an hourly blue-collar job where the boss isn't going to allow them to come in late or hung over. They live outside the city where they can afford it, and have to drive every day (potentially problematic). They can't afford to eat healthy, which adds to their health problems.
Health isn't only determined by biology and healthcare.
Wealthy people can hire people to do sober-required tasks for them, while they do the gladhanding and back-slapping and the strategic disinhibition of potential customers, suppliers, or partners.
This should be available to everyone and it's a tragedy it isn't.