I work as a dev like many here. Specially games. So lots of documentation lookup (or tutorials on what should be in documentation. Let's be real, games don't document a lot publicly to begin with, and public documentation is really poor for the tech industry), research on tooling for project, research to understand some new technical feature that rose up, spell checking for technical terms the built in dictionaries can't check, etc. I could go on for paragraphs, there's always something to learn, re-learn, or simply fact check.
and of course: discussions among communities talking about all of the above. Be it benchmarks, landmines to look out for, bug reports, highly opinated design choices, etc. Definitely couldn't find all this restrained to a Discord server or Facebook page.
And that's just all on the business end. Sometimes you just want to search up a reaction gif for a chat, or find news of the goings on (which is down on the weekend).