Most will find a job that doesn't require any of it anyway.
Think of education like a hill with plateaus. IF they manage to get high enough, sure they'll descend, but they won't forget everything and will be more capable later on. Ergo, they won't be stuck in a job that doesn't require 'any of it'. This can actually influence the whole job market.
Still, I'm a fan of tailoring primary education to the student - IE I think it's a good idea to realize that not everyone is going to college, much less right after graduation, and for those individuals it's better to concentrate on more practical topics - such as making sure they darn well know how to budget, balance a checking account, eat healthy, etc... Remember, learning isn't just about being able to do a job or develop a career. It applies in your home life as well. Lots of poorly educated people end up going to expensive tax preparation places even with dead simple returns because they can't do them themselves.
Don't just teach the Pythagorean theorem by giving them homework assignments with 25 problems telling them to find the missing side of a triangle; that's monotonous nonsense and will never encourage understanding, which makes everything less meaningful and therefore forgettable.
But word problems are 'hard' when you don't have proper understanding of basic English* either. It takes a mix; finding the correct balance depends on the class mix.
The problem with long breaks is that if you've just finished pounding a basic level of geometry into their heads, after 3 months of not doing it you gotta pound it in again. Think of it like a construction project - if you stop halfway through and just throw tarps over everything then come back in three months odds are you're going to have to discard ruined supplies, replace stolen ones, and redo a fair bit of the work you've already done because the environment ruined it. It's actually cheaper & easier to do it all at once.
Information loss in education seems to be geometric - a day doesn't mean much at all, even a week doesn't take more than 10-15 minutes to get swinging again. Let them go for 3 months though, and you're spending your day on admin stuff, the next week getting them back into the work habit, and the next several weeks reviewing to make sure they have the underlaying skills for whatever work you're doing.
*To be fair, any language the word problems are written in.