I've had my ravelry account for 15ish years, but fell off using it after about 2015. Here's a human-generated summary:
The content is a dream; the UI/UX is a straight up nightmare. 😅 Once you get used to it, it's a fantastic resource for fiber artists with a few main components to it: big libraries of information, the ability to track your various projects, and community discussion.
There's a pattern search with tons of filters to help you find your next project, and every designer who wants to get their name out there lists on ravelry. Photos from both the designers and users who have uploaded their project details give you an idea of what the project will look like. Tons of patterns are available for free, but there are loads more for sale as PDFs. There's also information on the different yarns out there (including users who may be looking to sell a particular brand/line/color/lot #) and yarn stores/sellers, both small/local and big box. The local yarn shop search is nice if you're in a far off place and want to bring home souvenir fiber or if you're trying to get an idea of what the fiber community is like in a new place.
The notebook/projects function is really powerful. It lets you keep track of everything about your project: your progress, what size tools you're using, the info off your yarn tags, pattern name/designer/link/images, and any notes you want to add. I treat my projects section like a lab notebook, making notes of any challenges I encounter with the yarn or the pattern, what resources and fixes I used, any changes I made and what the results were, you name it. If someone sees a picture of something I made, I want them to be able to see what I did to get there in the project page.
The community aspect is the big driver, though. Forums for basically every interest under the sun. Some designers have their own forums, which makes finding or getting human help with their patterns easier.
It's really, really easy to fall into a ravelry rabbit hole, same way it's easy to lose hours trawling Wikipedia when you get your hooks into something interesting.
Here's a look behind the velvet curtain (lol some screencaps from my account) for anybody interested:
