In 2022, I'd imagine there is some startup that does this. I'm not asking for something that truly scales to millions of users and has ALL the features of production reddit / hackernews. I'm thinking an MVP production app that has basic things that we all think about that a social networking app would have. I'm surprised that it's still so hard to find a "SaaS in a box" with some sample production apps like Twitter-clone/Reddit-clone, etc that does all the wiring for us.
You've asked for enough features here that make a low-code solution straight up impossible.
Also, if you've ever spent time on any freelancing site, requests like yours come in basically every other project. "I just want a social media app like Reddit/Twitter, here's $50 bucks and two weeks, let me know when you're done."
Honestly, it's a meme at this point, non-technical people asking technical people to build them a Facebook clone and completely failing to understand the immense complexity that goes into building anything for users beyond yourself.
Like I said, I'm surprised nobody here had given you a response like mine yet, given how common this conversation is.
Good question. This is in the B2B2C. I doubt I'll get millions of people per day LOL. So anything decent but something that I can quickly set up is what I'm looking for.