Working hours are fine. People don't work super long hours in Germany. You also get quite a bit of vacation time. The reason people don't have many kids (as is happening all over the developed world) is because the balance of incentives don't favor having kids. Kids are very expensive, both in terms of direct time and money spent on them and indirectly due to things like housing needs for families. And unlike in the old days, you can't just put them to work once they're 12 and have them earn money for the family or perform labor on your farm (because most people don't have a farm these days). Your kids won't realistically be able to produce any economic returns on all the money you've invested into them until they are well into their 20s or later once they're actually stable and have a career. And all the while, the upfront cost is gradually getting steeper and steeper. Housing is gradually becoming prohibitively expensive here in Germany, and even if you can afford what you need comfortably the supply is small relative to the demand. All these costs force young people to think hard about whether they want kids or not and force them to also wait longer before having kids.