I think that's a very good point. It's similar to how when you start learning something new, you'll make a lot of progress easily and everything will seem fresh

I think that's a very good point. It's similar to how when you start learning something new, you'll make a lot of progress easily and everything will seem fresh and original. After a while, you've discovered most of the big ideas in the field and have see a lot of what is on offer, so things start to seem worse and less original. A good way to test this hypothesis would be to check with people who are new to the scene and new to Hacker News. Do they react to the content similarly to how old members initially reacted?