The way that it was explained to me is college is an “indicator” that says a candidate was able to go to class, study, and pass an exam. These are things that tell an employer that you have the skills to schedule your life, do assignments, wake up, etc.
Bootcamps, certifications, etc. all show how you can do a specific thing.
I’m not saying I agree with it. Remember that when you apply to jobs, your resume and your experience is to get past the resume bot. College and certs are easy gates for a company to put in their bot to filter resumes out.