Is it really much worse now?
I am mid 40s and can remember a girl in my 1980s primary school class who hardly ever came in (incidentally it turns out she is autistic and is currently homeschooling her 2 autistic children) and lots of children who would be dragged crying from parents in the mornings.
An ex bf was a school refuser throughout primary and secondary. This would have been 80s and very early 90s. His mum was still scarred by the memories of trying (and very frequently failing) to get him in. He failed his exams despite being quite bright and had to retake them all at college in his early 20s.
A friend from secondary/sixth form had such severe anxiety and school refusal that she would be given work to complete at home and allowed to come in for part days. She sat all her exams in school but in a separate classroom.
A couple of the children who walked into school (secondary) persistently missed form time and assembly in favour of rocking up just before the first lesson. This was frowned upon, but they were allowed to go to the front office and get marked in the register, so I am assuming this was not recorded as absence at all.
There were quite a few boys in my year who would routinely miss a couple of days a week throughout secondary. They were generally considered to be 'bad kids' and it was just assumed they'd fail their exams - which I assume they did. One was the child of a local 'hard man' and another the child of a very solidly middle class family. He later fell into heavy drug use and sadly died young. I don't remember much about the others.
We'd all miss weeks or even fortnights for term time family holidays, plus days off for weddings, family gatherings, days out etc. No one seemed to care. Not passing judgement on whether this was a good or bad thing, just that absence was seen as unremarkable.