Most delivery driver jobs here pay $150-200/day depending on how busy the line is, and the people that work them usually aren't looking to move up instead they want cash wages for easy work, since most have records and can't get decent paying jobs anywhere else. The article is correct almost all these guy's still live with their parents. There were only 2 guys I knew that actually thought they could move up and make big money while the rest of us accepted we were only ever going to make $200/day and were essentially contractors, we were never privy to any gang internal business.
Gangs no longer hold drugs when corner selling (where you make the most money, selling by the point at full street value), they pay an addict in drugs to do this while they run security watching over the operation to prevent robberies. Street enforcer is where you start if you want to move up since you are essentially managing operations instead of just a delivery boy. You also hang around the top people as they call on you to come along to jack rival operations. These thugs get a lucrative percentage when they steal drugs off other crews and pass them down to the delivery lines to sell so are making real money, since it seemed every enforcer in my little dope crew was bombing around in a Porsche Cayenne customized to be bullet resistant with hidden compartments installed to hide their handguns, lived in huge houses by themselves and were always decked out in latest heatbag designer clothes. I don't remember any of these guys being broke, and technically they are the lowest rung on the gang hierarchy since the drivers are just contractors.
That was back in 2005 though, and now the vast majority of gangs are not handling any product here. Their income model is intimidation and extortion. It's far easier to wave a gun around on the street and tax everybody in the drug business than it is to put in work building up a line or managing operations. They don't even steal each other's lines anymore, just demand a percentage of the profits. As a result street violence has actually declined, since jackings and hits decreased and most beefs are now solved by passing money over a table. These independent dealers are also way better at selling drugs than gangs, so bring in much more money and the dominant gang that taxes them also offers protection from robbery (we are robbing you to offer our robbery prevention services).
This gangster method is more profitable, has almost no startup costs besides needing vehicles and guns, is much harder to prosecute since they never are directly involved in narcotics trade, and has an endless recruitment pool inside prisons to replenish ranks faster and with tougher recruits. It's also how all those Mexican border cartels operate. They are merely taxing the smuggling routes into the US skimming the shipments of Gulf and Sinaloa cartels. Those cartels have to build manufacturing, supply chain and retail while paying off politicians and police while the thug at the border just needs a gun, and is impossible to get rid of since they hold down their territory hard.
tl;dr Stepping into a gang as the new lowest position pays much more now, and is almost a guaranteed ladder to better positions since narcotics handling has all been outsourced as drug dealers are good at being drug dealers, and gangsters are good at being thugs.