In general, for the most part, young people who were born of ancestors who came here 200 years ago, or 150 years ago, or 100 years ago do not want to work in the trades anymore. Call them Europeans if that's what you'd like to say but feel like you can't or shouldn't. Day laborers are willing though.
I check in with a friend every few years who has the same type of business that the OP's friend/boss does. Last time was back in March. His main guy of 20 years moved back to Ecuador as of our previous get-in-touch call, so I was curious if he'd found a replacement yet. He hasn't, so he's going it alone. I asked if it's really been that hard, and he said beyond, and that day laborers without proper paperwork who are found in droves in the parking lots of places like home despot won't even get into his truck for under $300 a day these days. Doesn't matter that they many have little trades-skill and might have been farm laborers the month before. The ones who do have skill want $350 a day and often have an attitude. My friend's hypothesis is that the skilled guys are those who on the course of operating their own business as fast as possible and are only there to build the capital to get there, so they'll get in the truck but just don't want to be there, or won't do work they believe to be beneath their skill level.
This is not an isolated story. Many of my friends are business owners in the trades, from home improvement contractors to tree companies. Same story. Those of European ancestry don't want to do this work anymore is what they say, regardless of the pay. Can't find them unless they're a relative of another business owner. In contrast, most of the new arrivals are willing to put in a real work day, but they aint gonna do that for $18 bucks an hour.
I told my friend who's going it alone now that he's better off. He's got a lot to lose. Hiring someone who cannot be put on the books is a disaster waiting to happen. I won't do it, ever. Nope. So many things could go wrong. The implications are devasting to a legitimate business owner if they do. I've had workers who've gotten injured. Thank god I'm on the up and up. The costs are staggering on the front end, and on the back end I'm paying out on increased insurance rates. Thankfully negligence on my part was not deemed to be part of the equation, because it wasn't. They simply got hurt. It happens. Thankfully I wasn't sued. The lawyers they were required to have at the comp hearings tried to get the injured parties to sue, but they refused.
It's not easy being in business, eh?