I mean, I'm 25, married, about to have a kid, a nice house, full-time job, two months emergency fund in the bank (after buying my house this year), and a stupid monthly payment in student loans (larger than most mortgages with my wife and I combined).
I'm also from a poor class family, who worked up, got a job, etc. Because I'm white most burden scholarships I couldn't get, so I got a fair amount from research etc. I wasn't going hungry poor, but I did have to buy my own clothes, pay for school, lunch, what ever, at 14 poor.
Now, I've been planning since I went to school to start my own business. Next year's bonus (which is 2 - 3 months living expenses), plus tax return (estimated 2 months living expenses) gives me right around 6 months living expenses. That's 3 years out of school. There is no reason people looking to start a company cant be patient and get some savings first. I actually have two websites making profit (albeit small) at the moment:
https://easy-a.net/
https://projectpiglet.com/
Both of those were completed while on vacation from work or weekends. And both are growing rather consistently and I should be able to leave my current role in the next year. I grant it's a stupid amount of work (I work ~80 hours a week, or 12 hours every single day), but there is no reason people from a poor background can't have savings AND start a business.
Just a different perspective. Kudos to you for making it work though.