Where I live, long working hours are normal, but as kids get older, it's hard to maintain both parents keeping that up. Usually, one will quit or reduce (not always the mum). Or they get divorced in their 40s, to be perfectly honest, mainly because they never see each other! I only know one person who used nursery childcare though. Most people had nannies in the home. There are a lot of ex-banker types, who did that for a few years and then got out. These are mostly men, to be honest, as are the self-employed and entrepreneurs who work crazy hours, inc a lot if travel, but the hours are not fixed so it's hard to say 'how many hours' they work as it varies, day to day, week to week. This is a certain type of personality though. Not everyone can cope with the level of risk involved in that.
One of my daughter's friends always lived with her siblings and the nanny in the basement flat of the main house. The nanny attends all appointments and does everything, as far as I can see. In fact, everyone at the school thought she was the mum for years. This family are Russian and no idea what the mum does or whether she works or not. The couple live in the main house (about 4 floors) and the kids still live in the basement to this day.
The are many families where the mum doesn't work but they also have a live-in nanny. They say this is essential for facilitating different after-school clubs, school pick-up times, ferrying about and homework help. Some people have tutors who travel with them on holiday.
In general though, it gets harder to have 2 parents working 60 plus hours as the kids get older and need more help with school etc, plus they develop minds of their own! Unless you have effective family help or staff!
It's good that your DH can at least have a day at home with the youngest OP, plus do school runs. That makes a difference. But when do you actually spend time with him, never mind the kids?