Post-graduate education is kind of a raw deal for people with undergrad degrees in computational fields. It might actually be worse than "free labor", if you consider the alternative of going to work after your first degree.

In the US, you're looking at paying $20-50k/year, and while most students will get tuition waivers and small stipends, those often disappear if you do any contracting or work on the side to supplement your meager income.

Meanwhile, $100-150k is a reasonable starting total comp right out of school, especially after the recent rash of inflation. And a good worker can realistically double that in the 4-6 years that it would take to get a PhD.

So the opportunity cost is staggering, but wait - there's more. The job market for tech positions has been very hot for the past decade, and the global economy is on the verge of a rebound. If you want to learn about a specific field like ML or aerospace, you can just get a job in that field. Kids graduating today have the option of learning from talented and driven people while earning a reasonable salary.

Research certainly has its place; most of the work that we do is based off of concepts that were pioneered decades ago. But from the perspective of a prospective student in the 2020s, it's a hard sell.

Especially since the current advisor/advisee relationship is rife with perverse incentives. This whole wall of text assumes the best case scenario, where you don't end up in a toxic lab.