But it is poverty. It's a poverty of experience and opportunity, and a poverty of aspiration.
For example, a kid now is expected to have access to a computer and internet to complete homework projects. Local libraries with computers are quite a rare thing these days - so you can't just pop to the library after school and work there.
What happens when the laptop in that kid's family breaks, and they simply can't find £150 to buy a cheap replacement on Ebay? (which could well be false economy, as it's a gamble as to whether it will work after the year's guarantee)
How do they do their homework?
How do they research and apply for work experience, if they're teens at that stage?
All these things severely limit your ability to get on track for the supposed 'good job', even if for simplicity's sake we're assuming that 'good jobs' are a realistic prospect for most young grads.
So being able to pay rent and buy food is not the full story of poverty. The truth is you need a bit more cash to be able to avail of the opportunities of a developed society.
It is most definitely poverty when people are shut out from being able to improve things for themselves and enrich their lives, from a lack of money.
It's not just about kids either - think about people trapped in low wage jobs. Just try getting a 'better' job if you are shaky on the most basic computer skills, like Word or Excel (or more increasingly, Google office) because you don't have a computer, the item deemed a luxury because it's not food or rent or clothes 
Or you can't afford appropriate clothes or shoes for an interview.
But hey, as long as you have a roof and beans on toast and a warm jumper - couldn't possibly be poverty, could it.