I bought my first home with nothing down. First and second mortgage. Then government gradually increased the down payment to 5, 10 and now today 20%.Yes, not that long ago, people needed 50% downpayment for a house. There were no credit cards. You left home when you saved up enough money to move out. The world works just fine on savings. It's of course more difficult to become a billionaire, but it's something that the world can do without.
Probably more millionaires made in real estate than any other business.
You left home as soon as you had a job. The human is the only species that lets the young back into the nest.
Hard to start a business without credit of some kind. Who do you work for? Can they survive without credit?
There will always someone to lend you money as long as you want instant gratification.