Down to discretion would be that the headteacher and parents look at the child’s normal attendance, achievement at school, attitude at school, family finances, stage of school, etc etc and judge whether or not an additional 5 (or 10) days off would be ok. This is a much more sensible approach than a blanket “computer says no”.
My children have excellent attendance, none are struggling, and we are conscientious parents who would do extra reading and maths etc while on holiday if required. All my kids are in infant / junior school, none are preparing for exams. We take them out of school one week per year to go on a holiday which they wouldn’t be able to go on if it were limited to term time. It irritates me that as parents we aren’t deemed sensible enough to be the judge of this decision, one that affects MY children