If you're making near minimum wage, the absolutely last thing you want to do is work more than 40 hours a week. A low-income individual needs more time and energy than somebody with above average income. If you don't earn much, you will have to do a lot of things yourself and spend more time doing it; you'll take the bus instead of the car, you'll spend more time shopping around to save money, you may have to spend more time preparing your own food. If, say, you're taking on a second job, you're not increasing your standard of living; you're mostly just increasing your stress; you're increasing your income, but also your cost of living (generally dramatically more so if you have children).
You mention Germany: Germany does not have a statutory minimum wage; however, it guarantees you certain minimum living standards as long as you are working or actively looking for work (or, of course, if you're disabled, too young, too old, etc.). This includes a roof over your head, comprehensive health insurance, and enough money to get by (if you earn too little, the government will top it off). It's a frugal life (even if it's technically above the subsistence level), but one that can be managed and one that you're not improving on by working extra hours.
If you want to improve upon that situation, your best chance to accomplish that is to acquire extra skills, not to commit yourself to becoming a wage slave. If you're fine with that standard of living, your quality of life will be better by only working 40 hours a week and having 4-5 weeks of guaranteed annual vacation time rather than working 60 hours and not having any vacation time.
You mention Germany: Germany does not have a statutory minimum wage; however, it guarantees you certain minimum living standards as long as you are working or actively looking for work (or, of course, if you're disabled, too young, too old, etc.). This includes a roof over your head, comprehensive health insurance, and enough money to get by (if you earn too little, the government will top it off). It's a frugal life (even if it's technically above the subsistence level), but one that can be managed and one that you're not improving on by working extra hours.
If you want to improve upon that situation, your best chance to accomplish that is to acquire extra skills, not to commit yourself to becoming a wage slave. If you're fine with that standard of living, your quality of life will be better by only working 40 hours a week and having 4-5 weeks of guaranteed annual vacation time rather than working 60 hours and not having any vacation time.