I’d argue the other way - open source in 2000s to central libraries were of decent quality. The quantity of code now these days is so much and of questionable quality - everyone and their bootcamp writes code to GitHub and call it open source, just to show they have open source.
Hell, I have public code on GitHub, but I’d never put it on my resume.
There may be a signal-to-noise problem, but the amount of useful open source projects and the extent to which we rely upon them has only increased in the past 20 years. “Open source” includes projects like Go and NodeJS, which are hardly trivial, disposable projects like you’re referring to. Pretty much all crypto is open source and people have invested tens of billions in that ecosystem. I could continue and list at least half a dozen projects that are considered critical infrastructure which are developed in that fashion.
Hell, I have public code on GitHub, but I’d never put it on my resume.