Its a multitude of things that add up.
I was a smart kid from a poor but engaged household. So we had a house full of books, I could read fluently at two, but no one had been to uni and we had no idea how to navigate ‘the system.’ Crap sink schools, zero expectations at school but supportive home.
When I did get to uni I found the academic work easy enough - what was truly alienating was the social capital others had that I lacked totally. I almost had a breakdown my first year because of this - it was a very odd experience.
If my parents had been less engaged, or I’d been less smart/stubborn or we’d had a chaotic household I’d have sunk. No doubt in my mind about that.
Now I’m married and have kids and we are in a higher (not insanely high, just comfy) income bracket, and the kids are growing up in a bilingual household.
I see constantly things I do for ds or that he gets to do that I would simply never have had on my radar. The language gap was never an issue for me because I was a voracious reader but I can see how it happens and how it disadvantages. At work I can see who reads and who doesn't because their language skills are poles apart and I see those people interact with higher management in a totally different way than I do. I have a very neutral/RP accent and am fairly eloquent and I’ve been told I’m hard to place - ie they cannot tell I’m from a sink estate in Yorkshire, I might be ‘one of them’ and so I’m treated differently.
Rambly post, so sorry, but income links to so many things - status, how you speak, the cultural and social milieu that influences you. It’s not purely money=success. It’s what money is often (not always) an indicator of.
And of course if you’re poor you’re not stupid. I was poor, I’m not stupid. So much of poverty is structural. The point is that poverty is bloody hard to get out of and a child starting from a poorer background is starting with a massive disadvantage.
I’d like to see equality of opportunity - much better investment in pre schools, Scandinavian style. There the system is that everyone, from the poorest to royalty goes to the same schools. Kids get fed, everyone can afford it. it’s mainly play based but they accrue those experiences, the language skills, etc all together.