I wonder if there is any legal standing for users to sue Reddit for a fair share of those profits. That’d be nice if it could happen. But i suspect, probably not.

Yeah, probably not. When you sign up and agreed to their ToS, they don’t “own” your content, but you grant them a worldwide, royalty-free, perpetual, irrevocable, non-exclusive, transferable, and sublicensable license to use it without compensation.

From their ToS:

Any ideas, suggestions, and feedback about Reddit or our Services that you provide to us are entirely voluntary, and you agree that Reddit may use such ideas, suggestions, and feedback without compensation or obligation to you