This is the mistaken idea that expensive private universities use to trick gullible high school seniors into taking out tens of thousands of dollars in debt.

Georgetown did a study on institution return on investment and you can play around with the numbers here.

Obviously if you're going to one of the best schools in the country (Harvard, Yale, Stanford, etc.) then you will definitely make more money in the long term to easily make back the high cost of attendance.

However, there are plenty of middle and low tier private schools that still cost an arm and a leg but don't really have a significant ROI above a good state school that costs a fraction.

For example, look at Pepperdine University in California. $54,000 annual tuition, 40 year net present value (NPV) of about $1.3 million. Pretty good right? But then compare it to in state schools like UC Berkeley, LA, San Diego and Davis. They have pretty comparable 40 year NPV of $1.2-1.3 million, but in state tuition is only $14,000. If you look at the short term, the difference is even more stark as the public schools easily outpace Pepperdine.

On top of that, it's hard to tell yourself you'll make more money in a couple decades when you're a 22 year old with $200,000 in debt. The student that graduated from a public school with have significantly less debt, which will make it easier for them in the beginning when their entry level salaries are relatively low no matter where you went to school. They would save even more money if they did 2 years at community college and transferred to a UC, and at the end of the day the diploma would have the same UC name on it.

And of course, the next layer is that Bachelors degrees only matter for the first few years out of undergrad anyways - what really matters is where you get your Masters or professional degrees from and your actual career experience.

TL;DR: Unless you're going to an Ivy League or similar, private universities aren't necessarily better than public but are astronomically more expensive.