To start with the majority of university grade education itself does not demand a productive scientist or researcher at all. So cut it out already and focus on making these individuals skilled teachers. The students deserve as much. That is after all the core business of our current system.
Then identify talented students to transfer to true research facilities to master their art. This should not be done, except tangentially on the basis of marks which is another flawed part of a presently gamed system. My son passed a forth year course ( applied science ) by attending no lectures whatsoever and by working through the exams of prior years and got a mark of 100%.
I think that makes the point. Today we have millions prepping with past SAT exams to optimize their marks. Without any of that, I nailed 1400 SAT ( combined math and English ) in 1967. No one got to prep as they do today. At best they provided a warm up exam to establish familiarity.
I do think is is possible to sort out real talent through some effort. That is what needs to be both encouraged and guided.
Today we have a massive amount of junk science flooding out the good stuff. And it is a flood. Worse, most researchers have been so tightly channeled that they dare not stick their heads up in any other part of their own field. that cannot make them productive.