Is life fair - obviously not. Can outcomes be changed, yes - though to date, sadly not for everyone. All most people can do is try to work out how and what might make the most difference to their own families outcomes. That’s reality, once every once in a while someone altruistic comes along and changes outcomes on a local level. For most people this probably won’t unfortunately happen.
Previous waves of immigrants, have come to these shores with nothing, and some of their children have flourished in our state education system. Not all have, by any means, but if some have, it must at least be possible for children to succeed against the odds.
Engage with your children's development from day one, certainly the younger the better, and seek all means to secure free and low cost help for you to help them, this is so much harder to do if you are time poor.
I know how lame this will sound to anyone working 2+ low paid jobs to survive.
Use (free) libraries, use the computers in libraries, use any free courses to learn to use the computers - find out what is available in your area, what can help you, to help your family.
Look at books with your children as soon as they can sit up, pick up second hand books at charity shops, car boot sales. As has been mentioned, go to places like free museums. Fire up the imagination of young minds.
On parents evening, especially at primary school, ask your children's teacher what they will be learning in the next term then if it’s at all possible, take your family to a museum that covers that subject. Or borrow library books that could bring the subject alive for them.
I didn’t ‘hothouse’ my children, but we did play lots of simple ‘word games’ often made by using the inside of cereal packets. (Such as pick up the pairs, one syllables words: ‘the’, ‘at’, ‘ in’ etc which helped with their reading). It doesn’t have to be intense, but it does need to be consistent, early foundations in education lead to better exam outcomes later.
Our birth families did not have the benefit of a University Education, but our children have, and my husband has, through Open University.
Good luck to everyone aspiring to level up.