Nothing, except that:

a) not everyone who figured out higher education is a racket wants to do 180 degree career turn

b) many people would like to make their future in something else than easy code monkeying money

If everyone goes to write NoSQL serverless CRUD for adtech, who will be left to do research or something actually materially productive in the economy?

For one thing most tech internships want you to contribute to the business. Unpaid internships that involve doing real work are illegal in many industries/locations.

In some places if you have an unpaid tech internship, everything you do has to be an artificial training exercise for the sole benefit of the students.