I've been a teacher; still work j teaching now.
As a child I always had one - two weeks out of school for a holiday. Dads factory shut down was term time and that is when he was able to have a holiday. So we did too. We didn't in exam years but rest we did.
We all were fine. We caught up, we did well educationally.
We've never taken Dd out for a holiday - as I work in a school and can't miss days obviously.
However I truly don't think a primary school aged child is overly disadvantaged by missing 1-2 weeks of school. So long as you're by missing the first few weeks of a year, and not hitting exam times - well, most stuff can be caught up on by pupils with parents helping. Don't expect schools to provide work and catch up stuff, but ask what is being covered and most teachers will let you know ime.
And nothing is only done once - seriously.
Yes, many holidays are just sitting on a beach or theme parks or whatever. But that time is not just about the destination. It's so much more. A time when the whole family are together, sharing relaxing time without the restraints of work, housework, school, etc. People are often more relaxed and in a different frame of mind on holiday, and children benefit from that type of time with parents. I do believe that people of all ages benefit from time away together, as a family, away from the home. I know not everyone can do it - but where they can't it's good for them.
And whilst prices are so vastly different in term time compared to school holiday time - then people will always be swayed by that too. And who can blame them?! When you can save over £1000 on a weeks holiday it is often the case that it is then or not at all.
And obviously the choice of choosing a different type of education is not available to everyone. Home schooling is not a valid choice for many people - people have to work to earn money to start with, and can't just leave their children home alone!