Vast majority of people, including the poor, are employed. Even in countries where their labour is worth very little money because of lack of infrastructure, training and capital investement the economy still finds use for their labour at some price point. This will continue to be the case, I would argue, forever (unless we go extinct).
The fact that the economy finds value in even the least productive labour is illustrative in the complete fucking bonkers picture of how shit works that we're dealing with here. The world's economy isn't broken down into trained professionals who are awesome and everyone else is useless. The way things work is that there's stuff that needs to be done, and vast majority of stuff that needs to be done is local, or to put it another way, you need a guy in the same town/neighbourhood to come over and do it because you're busy doing some other shit that's a better use of your time. THIS IS VAST MAJORITY OF THE FUCKING ECONOMY EVERYWHERE IN THE WORLD.
Now sure, when you look at the GDP most of the wealth is generated by highly trained professionals so we tend to worry about how do we move those people at the bottom of productivity into the bracket where their labour would be more useful. It's a valid concern. What is not valid is to make the leap from the fact that there's a relative disparaty in productivity to the blidningly idiotic conclusion that the poor people are of no economic use. By virtue of being a human being with a brain and a pair of hands they can participate at some price point in an enormous amount of economic activity to free up people who are more productive because a) they have better infrastructure around them b) they have better access to capital c) they're better trained or d) they're more naturally gifted.
It's also worth noting that only one of the a), b), c) and d) reasons for why there's a disparity in productivity is essentially unfixable through more investment. And the thing to note is that the disparity in productivity is mostly explained by the other reasons.
The right way to think about labour, and I probably have said some version of this a million times, is to consider human beings to be super-valuable intelligent agents that are potentially capable of an enormous variety of economically valuable activity, given the right circumstances. Lots of economic inequeity is a consequence of circumstances and happenstance, rather than immutable genetic stuff. This is why immigration is undeniably good, as it shifts labour from shitty infrastructure to good infrastructure thus making it more valuable. This is why training people and educating them is valuable. It all flows from the same basic undersanding of labour as a resouce. It's not destiny to be poor, we don't have to have poverty, we have it because the policy choices we make are bad.