It makes me sad when I hear people say things like this. A college education has the potential to be so much more than this.
I took a poetry class, despite not being particularly interested in or appreciative of poetry and it opened my eyes and made me a life-long lover of poetry ever since. Philosophy courses taught me how to think more rigorously and question things many other people take for granted.
There were many other courses which weren't required for my degree that I sampled and wound up loving and learning to appreciate things I never would have otherwise been exposed to... even changing my major because of some of them.
I didn't even have any truly amazing teachers either, so I can only imagine how much better is the college experience of those who do. Having great classmates who inspire and motivate you can be fantastic too... not to mention the potential to make connections and broaden your horizons in all sorts of academic and non-academic ways.
College can change your life, change the way you think, open your mind and open your eyes, and so much more.
Learning the Big O Notation performance of algorithms that traverse data structures isn't so you memorize all the different running times in perpetuity. It's so you realize that performance and the type of operations you want to commonly execute are something you need to consider for the data you have to work with.
If you didn't learn that from your college CS courses, I don't want you working on my team.
Note: I am not saying non-college grads cannot commit to a long term goal, there's plenty of reasons people don't or can't go to college. I'm only saying that a college degree is a signal.
Its also my experience that as you get more senior and focused on a specific skill (I'm an iOS engineer), interviews tend to focus on that skill more than leetcode. I think there are a few stalwart holdouts (facebook + google), but I have interviewed with several trendy big tech companies and none of them asked me pure leetcode - it was always framed around my iOS skillset.
However, for a junior engineer there is no way to evaluate this kind of skillset since it doesn't exist - so Leetcode is a resonable substitute.
Actually, if you think about it, the whole concept of getting a college degree isn't much different - its not about what you learn in the classes, it just shows that you have the capacity to go through an arbitrary social experience, follow a bunch of rules, learn some stuff, and stick with it for a few years - pretty similar to a job.