I have a pet theory: there are managerially-minded university graduates who value prestige more than power or pay. In the post-War era, they became beige-suited company men. In my generation, they went corporate finance. Today, they work for private equity.
Banking was great. Everyone–from liberal arts to engineering majors–could putz around for years in a pre-defined and prestigious path with moderately above-market pay and the potential to become rich. (Most don't.) It was also a field that could absorb a lot of grunt work, because most of what these folks did was format PowerPoints and populate Excel templates.
After the GFC, bulge-bracket finance became less prestigious right when technology lowered the industry's hunger for grunts. Silicon Valley took up some slack, but at least until the pandemic hiring boom, there was a modicum of technical gating factors.
The entire time, corporate and industrial America needed administration. But working at a chemical plant in Baton Rouge isn't sexy. You know what is sexy? Working for KKR.
So KKR's partners buy the plant, hire the college grad, give them a few weeks' training and "deploy" them to Baton Rouge. That will be their "project" for years. There are perks: they get to fly in from a city, for instance. But overall, the partners can acquire this labor cheaper than their portolio companies. (Ask anyone who isn't a partner at a private equity firm what they do, and it's on a spectrum between administrative assistance and middle management in a random business.) It's what consulting did in another era, re-branded for what young people willing to take less pay and power predict their peers and parents find prestigious (and what they consider safe).