"No one is barred from applying."
Like I said, that may be true in theory but not in practice! Bars may not be set up deliberately but they can still exist in the perception, and so that perception has to be challenged. Sometimes by brute force, if necessary, until there is no longer any such perception.
As a case in point, Oxbridge applications are open to all, but there is still an overwhelming majority of such applications from private school education -- in part because there is an industry of encouraging and aiding applications in private schools that doesn't exist in the state school system, but also because many state schools still perceive Oxford and Cambridge Universities as elitist. They are wrong -- but the perception is real, and has denied many a capable state school student from even considering an application in the first place. So the universities set up outreach programmes to change these perceptions, and gradually the relative balance between applications is changing in the right direction. Were that not the case, many totally able students might never have bothered to apply, and would therefore certainly not have been accepted. The standards for acceptance never changed (hopefully), but active encouragement have ensured that the application pool is as large as possible, so that the final selection of candidates is far more likely to be the most talented. (For the record, this didn't quite apply to me, as though I came from a state school background I'd already decided I wanted to apply to Cambridge when I was 12, long before I had a chance to perceive the place as elitist. For others at my school, including some who ended up going to Cambridge, I'm fairly sure the outreach programme was quite important in helping to persuade them to consider it, and they were ultimately successful. The University, and the students, benefitted from encouraging diversity.)
Just saying that you have an open application policy and hoping that things will osmose naturally to a state at which the applicants, and then the workforce, are a roughly proportionate reflection of the diversity in society, inevitably means that you will wait a long time. And during that wait, you can be sure that at least some would-be applicants, totally capable of the job, may never apply -- because wishing does not make it so. It takes work to ensure that equality is realised.