This is nice to hear and congrats, but I'd be willing to wager that your project didn't get you your offers; your interview performance got you your offers. Yes, your project gave you something interesting to talk about, and of course, invaluable experience building an operating system. But that isn't enough, and it never has been when it comes to obtaining employment.
The ROI is simply bad compared to grinding LeetCode/NeetCode/Cracking The Coding Interview and learning how to game the interview process. This should be every new grad's priority if they are interested in employment. It's even worse than just having gone to a highly reputable university, ideally with a pipeline to FAANG companies.
To clarify, the reason I say that the projects led me to offers was only because they helped lead to the process being started (I.e. led to a first interview). Indeed, other skills are necessary to close the deal.
The way I see the current market, the hard part isn’t the interview-to-offer ratio, it’s the application-to-interview ratio. Grinding leetcode and improving your skills unfortunately doesn’t help you with that. Having a good resume helps (or having good networking).
Referencing back then to what I said originally, everyone has a degree, no one has work experience. Given this, having a cool project is one of the ways to specifically increase this application-to-interview ratio.
However, given this analysis, putting more effort into networking could yield similar results, so this suggests the original point possibly has some truth.
The ROI is simply bad compared to grinding LeetCode/NeetCode/Cracking The Coding Interview and learning how to game the interview process. This should be every new grad's priority if they are interested in employment. It's even worse than just having gone to a highly reputable university, ideally with a pipeline to FAANG companies.