From other comments that are focused on the code part of the subject, I think there are 2 big forgotten points here: time and hype.

Time: since platforms are big machines, their timeline and backlog is huge, and the self-taught geek does not consider (care) that. So when there is an obvious little hiccup somewhere, they create a bug report that asks for details, proof, reproduceability,... and finally get pushed back to eons because there are more pressing concerns to attend to at the platform level. Meanwhile, it takes about 1h (without AI) to code a workaround and feel like a hero because "I've fixed something that took them 3 years to triage".

Hype: yes documentation and code quality and all matter, but it matters even more when it comes from Google or Meta! We all feel little compared to giants and when they open their internal secret tooling framework (with big marketing budget) then we all feel like there is a secret to grasp and a key success factor to wield. So it is not so much whether a npm library some nobody created exists, but whether the main contributor works at a big brand name. It does not prevent smaller anonymous projects from emerging but lets face it, it is much more appealing when it is how Cloudflare handles it at 1e20 scale (because we all feel we face the same challenges of course).