This is somewhat of a random question and I assume it can only help but do Github stars mean anything to big tech (1k+ stars) and is "gaming" it a good use of time? (By gaming I mean honest accumulation of stars where the project is popular but not technically challenging)
Yes, I know several examples of engineers who have been hired into top-shelf Big Tech companies from their GitHub contributions. 1,000+ stars on GitHub is a lot. That generally means that your repo is being used by tens of thousands of developers at least (engagement on GitHub is naturally fairly low as it's not social media-ey). If it's a more consumer-facing library, your code could be reaching millions of users through the apps and websites your integrated developers are making.
By gaming I mean honest accumulation of stars where the project is popular but not technically challenging
Recruiters have 0 idea what's technically challenging and what's not. They only know what has traction and what doesn't. This is why I tell earlier-in-career engineers who are looking to break into Big Tech to not worry at all about "technical depth": Just make useful stuff people care about. Technical depth is highly subjective, and it's a subject recruiters aren't really equipped to digest.
I actually have fairly related personal experience. I didn't make big open-source libraries, but I did make a lot of free Android apps. I have many apps that got 100,000+ installs with 2,500+ reviews (mostly 5 stars). The developer email connected to those apps is completely separate from all my personal info, but I got recruiter reachouts from Instacart, Uber, Square, and many other very large tech companies that are generally considered top-shelf.
If you're interested in how I made so many successful apps, I made several videos about it: