For that to happen, I believe that interacting with people from other instances and moving your community and account from one instance to another have to become possible / easier.

At present, people flock to the instances with most users as those often have more local content (local content is generally easier to find than federated content) and they often have a smaller risk of shutting down. If I create a community on a smaller instance, the chance of it being found and interacted with are also much smaller than if it had been created on a bigger instance (because of, as I said, local content being user to find).

Sure, I can create an account on myfirstlemmyinstance.com (example URL, not an actual instance) with 10 users, but if my instance decides to shut down, my community of, say, 500 users will now have to move somewhere else and all old content will be deleted.

Ideally, I think no one instance should have a million users to begin with.

That probably also depends on what instance your own, I am guessing. A lot of them are experiencing such a large and unprecedented influx of new users, it’s often hard for them to cope with the existing hardware they’re running on.

I think it will be similar to how it was on Mastodon. I created a Mastodon instance back during the Twitter exodoi and had a big influx of new users. But those users only posted maybe a handful of things until they stopped logging in altogether. So I am now left with like 400 registered users but maybe a few dozen or so that are still active.

Better UIs is definitely one of the main problems for mass adoption I would say. I don’t have any trouble using it myself, but it can be a bit clunky.