"Lately, my students keep telling me why what we are learning is not important. They ask me when will we use this in the real world?"
There's a quick reply to this that I think people won't like, and you would have to be very careful using, but actually makes a more serious than it first appears. One possible answer is: "You're quite right. You don't need maths to mop the toilets out for a living. Is that your plan?" Many people do end up in basic jobs. There's nothing wrong with that, if that's genuinely what you want out of life. And many people who do it are happy and fulfilled with their lot. It's their life. You just need to be sure it's an informed choice, that they're going into with their eyes open to the consequences.
But really you need to find out why they're asking. It could be that they genuinely find it hard to connect what they're doing to real world applications, or that they do see a need for maths in daily life but not the stuff you're teaching. (People need to do things like fill in tax returns, pay bills, plan finances, calculate interest for loans, run a business, calculate fuel usage, buy supplies in the right amounts, understand economics, etc. Maths lessons often don't teach any of that.) In this case, find out what they want to do with their lives, or what they do do, and then give examples built around their particular applications.
Or it might be that they don't enjoy it, feel they're not good at it, and are seeking some excuse not to do it, or a reason not to feel bad about not being able to do it. Dismissing it as "unimportant" is one way to do that. In which case, it's a waste of time giving reasons why it really is essential - that just makes them feel even worse. There you need to build their confidence, help them catch up.
Or it may be a cultural issue. Sometimes people belong to a cultural identity that has negative views about maths and studying. Girls may think it's a "boy's subject". Boys may think it's "unmanly" or "geeky/nerdy" to be studious/academic/clever (as opposed to being physically tough, good at sports, etc.). Teens are very sensitive to what characteristics are seen as attractive or unattractive to the opposite sex. Sometimes you get racial, religious, or class stereotypes, where studiousness is associated with particular groups that are negatively regarded, or where there are strong religiously-based expectations that oppose, for example, girls studying, or the adoption of Western values, or non-religious values generally. Where gangs and criminality are a problem, respecting authority and conforming to the expectations of mainstream society are often seen very negatively by their peers. Friends, families, and communities all apply social pressures. Cultural conflict is a much harder problem to solve. There may be a way to fit mathematics positively into their worldview, but it may be that the only way is to tackle it head on and change their worldview, and that obviously has some very serious ethical complications that need to be considered first. Is is right to destroy elements of their culture, even if it is "for their own good"?
Without knowing what their issue is, trying to come up with solutions is a very broad question. Ask more questions about what they want from life, what they value, and what they think they have to offer. And be open to the possibility that maybe they're right, and maths is not what they need.