Why is it assumed to be harder to bootstrap a Reddit-type site today?

How do you get millions of people to decide to stop going to whichever site they are currently going to and go to your site instead?

All of these. Jonah Peretti has a good explanation here:

https://medium.com/matter/buzzfeeds-jonah-peretti-goes-long-...

It's not impossible, but it is much much harder.

Reddit has the moat of being the simplest thing that might work.

If you have domain expertise or just domain interest, it’s easier to start a new subreddit than build a new platform. Because you offload a bunch of busywork like security and ddos prevention and account verification.

Of course UI comes along for free too, but content is king.

So content not UI is where to start if you’re building your own thing. That means focusing on a specific audience, not everyone.

And it means having exclusive domain knowledge and/or enthusiasm. And so that means attracting experts.

If that expert isn’t you, it probably won’t happen. Assume other experts already have sufficient online outlets for online expression.

Basically if you build it they won’t come. Build it anyway if you must. Don’t build it for numbers.

Good luck.

> Is it just the discovery itself that would be hard? Is the market already over-saturated with options?

These two. There are a bajillion dead or deserted Reddit clones.

> Is it because they have a shorter attention span and would get too bored with a slower website?

But this is possibly a factor too. Reddit doesn't have the instant gratification and engagement of, say, Discord or TikTok.