To what extent are paywall journals harming junior researchers?
I wonder to what extent is this opinion shared and supported by the community?
Possible reasons this affects particularly junior less known researchers:
Other people make less efforts to search for their articles elsewhere, even when free copies are available elsewhere (e.g. on the arXiv or their homepage).
Especially well-known people are busy and not always "tech-savvy" and the articles might not be critical enough for them to cite, if the process is not sufficiently easy. A notable evidence is the following quote from page 61 in this paper by Misha Gromov:
Non-accessible Articles. There is a dozen or so other papers on Gehring linking problem but, since they are not openly accessible, one can not tell what is written in there.
With fewer citations, especially by well-known experts and widely read articles, the authors miss out big time on their opportunities to become better known. As the authors of these "non-accessible articles" missed their chances to be cited in this recent long paper by Gromov. Especially for junior researchers without permanent job, that can make a big difference for their future.
Another byproduct of the fewer citations and obstructed availability are more limited opportunities for finding potential future collaborators, especially from neighbouring fields, where people again might not make enough efforts to search for a free copy.
Junior researchers with less experience are not fully aware of (or are not being well explained) the benefits of putting their articles on the arXiv, updating to the published version and explicitly confirming the preprint copy is identical with the published one, to make it easy for people to cite who do not have access to the paywall version. In a way, junior people are trusting the journal system that seems to be silently failing them without their own awareness.
Perhaps there are further reasons or evidences?