They are the poorest of the poor.
No they’re not.
For economic migrants, the decision to leave is generally a conscious choice by relatively well-off individuals and households to enhance their livelihoods … Clandestine travel costs anywhere from US$5,000-$35,000. Many of these migrants are petty entrepreneurs who sold their businesses or property in order to pay for the expensive trip.
I think even that writer may have put some lipstick on the pig. Petty entrepreneurs, sure; but in sinkhole Third World countries like Niger or Eritrea there are other classes of people who can get their hands on a few thousand dollars. There are minor government functionaries—cops, for example—with jobs that allow them to squeeze bribes out of their fellow citizens. There are also, of course, criminals.
A thing you notice about these illegals from the news photos is that they look well-dressed and well-fed. Some are positively chubby.