I love Reddit, but I find their story depressing. Everyone has fun personal projects that they make, but a lucky few will have them become wildly popular without much planning for reasons they can't foresee. I don't feel like I can learn anything from that, and it makes me feel very unlucky and that fate is largely out of my control.
No one denies that luck plays a big part in how successful any given startup will turn out to be.
But everyone can do things to make their chances of success higher, and the magnitude of that success greater, through the way they conduct themselves and the decisions they make about what they do.
Luck was a big factor in Reddit's early success. But luck wouldn't have helped them if they didn't have a good idea ans put in the work.
And luck, as they say, is something you can make, by spending enough time operating with determination, conviction and sincerity, and by learning enough about the world to pick projects that will have a higher chance of success.
But from your comments in this thread, you seem like a pretty cynical, defeatist person, which could be a pretty big handicap in your quest for success - if indeed that is something you really want.