Children can change schools if current one isn't working for them (like chaging jobs), can be home schooled (wfh), flexible schooled (part time), state schooled, private schooled. So there are choices, but not attending isn't one of them, just like not attending work isn't a choice for most adults.
And many lower paid adults don't have option to wfh, that is a choice more linked to professional roles. Carers, cleaners, porters, health care assistants, teaching assistants none of these can work from home.
But getting a good education now means children are more likely to have greater choices when they are an adult. I am in a high demand professional role, I can dictate my hours, my working pattern (home vs office). My friends who are in low paid roles have no flexibility, miss their child's schools events, can't go part time as if they do they don't earn enough to cover their bills.
Yes, I agree schools need to support children more, but they can only provide this additional support (counselling, booster sessions for those who are struggling etc) if the children are actually in school. My daughters school has a wide range of supportive options such as free breakfast clubs, 1 to 1 pastoral support, subject booster sessions, homework clubs, an ARP for those who cannot cope in their classroom, home tutoring. But the headteacher says, those who would benefit most are those who are often absent. Those who are absent due to anxiety, she has offered for a specialist teaching assistant to visit at home daily for a period of time if child feels unable to attend. And when the TA gets there, the child isn't even home, and the next day they aren't home, and the next, and the parent doesn't pick up their phone, so she has no choice but to report to social services as a missing child. This all takes up valuable resources. She knows they are probably on holiday, but has to follow procedures. This all costs money which could be better used elsewhere.