I think that one of the difficulties around school attendance arguments is that the one of the strongest arguments IMO is one of 'common good' [rather than individual benefit].
In general, in this country in this day and age, we are more focused on individual benefit, and less susceptible to being swayed by a notion of the 'common good'.
To illustrate:
If I have a class with 32 children. If on average each one takes 5 days' holiday each year, then at every point I could have 1 child missing just for that reason. On their return, in order for them to access what we are learning next - e.g. writing about characters in a book [that they haven't read], doing word problems [using a maths technique they haven't learned yet], designing an experiment [to test a principle the rest of the class were introduced to the previous week] - an adult will tend to spend additional time with that child to catch them up, at least enough for them to be able to do the day's task. As not every day has every subject, it will take about a week for that child to be just about sketchily caught up on the critical bits of what they missed.
In the meantime, the 'common good' - the progress of the other 30 children (remember on average 1 will be away this week too) is marginally harmed, because the adult catching up the child who had missed a week is not available to help the other children.
Then the next week, it is another child who has been missing, so again the adult spends that time with the child who needs to be caught up, and the rest of the class, marginally, suffers... and so on ad infinitum.
It is that constant 'drip drip' of disbenefit to the rest of the class that is, to me as a teacher, the main problem with term-time holidays. I necessarily - in order to enable your child who has been on holiday to access the lessons I teach when they get back - make certain that the direct disbenefit to them is as small as possible, by allocating my own or another adult's time to them. But the cumulative marginal disbenefit of my teaching time being thus redirected is an issue.
I realise that the 'common good' may not seem important to many of you - 'it's my own child that i care about, and they are not harmed' - but that is how i as a teacher see it.