Why did you "help" (in other words make a post/comment) that person on Reddit? Because you enjoy it, you enjoyed reading posts and comments by strangers, replying to them, and seeing your comments accumulate upvotes and other comments. Reddit gave you that experience for free.
Reddit also occupies the space that otherwise might permit a more useful, benevolent internet platform. From a certain perspective, Reddit is standing in the way of an internet that better facilitates the enjoyment you describe.
You could say that about nearly any good thing in life. Your current job/relationship may be holding you back from an even better one. Those leftovers you grabbed out of the fridge are occupying the space that could be taken by an even better meal. Every minute you spend watching a TV show you've already seen or a videogame you've already played is taking away time from your finite lifespan you could be spending on new, novel experiences.
If there's a better platform for giving you what you want, I'm sure you'd leave Reddit and never look back. If this platform you're imaging doesn't exist, how do you know it even could ever exist?
