Initially, LinkedIn was just another site where you could find jobs. It was simple to use, simple to connect with others; it even had some friendly groups with meaningful discussions.
And then it gained monopoly as the "sole" professional network where you could actually land a job. If you are not on LinkedIn now, you are quite invisible in the job market. Recruiters are concentrated there, even if they have to pay extremely high prices for premium accounts. The site is horrible now: a social network in disguise, toxic and boring influencers, and a lot of noise and bloated interface to explore.
When Google decided to close their code.google.com, GitHub filled a void. It was a simple site powered by git (not by svn or CVS), and most of the major open-source projects migrated there. The interface was simple, and everything was perfect. And then something changed.
GitHub UI started to bloat, all kinds of "features" nobody asked for were implemented, and then the site became a SaaS. Now Microsoft hosts the bulk of open-source projects the world has to offer. GitHub has become a monopoly. If you don't keep your code there, chances are people won't notice your side projects. This bothers me.
Rant over. I hate internet monopolies.
From my PoV it's probably many of these projects are effectively public good spaces. Hosting a code repository has become less of an esoteric thing and turning into a public good benefit (like a physical library but virtual for code). Spaces like Reddit and Twitter are todays analogous of a public discussion forum in a park or at a bar.
Internet tools have become so ubiquitous they are critical to serve public needs and public benefits. However these internet spaces are increasingly commercialized and privatized, which runs against them being valuable public goods (see the difference between Wikipedia, run primarily for public benefit, and Wikia/Fandom).