Curiously, even if the quality is lower the open platform would presumably still win. There are a huge number of people in the category "desperately need to know, but don't realise that their need justifies paying to know". The sort of person who is comfortable reading an academic paper and will cheerfully implement something from arxiv, but their employer considers them a boring coder and isn't about to pay for access to a paywalled journal. Such people turn up in every discipline.

And academics have an incentive to get their ideas out there so have a tension present when they want to be published in a journal. It is easy to imagine unpaywalled research dominating paywalled. Who cares what people write if it can't be easily read? There are a lot of smart people out there...