I told somebody I know who knew about Reddit's API changes about Lemmy. He has a master's degree in Computer Science and works as a software engineer. But then, he told me that it's too confusing to get into, even for someone like him. This is great feedback and I hope that these issues will be fixed in the coming months.
I do agree that the average Redditor will not only not switch, but will probably continue to use Reddit, at least until the 30th. We'll see what happens after that. That being said, I think that's a good thing. Reddit has 500m MAU. Not sure the fediverse is up to the task just yet.
In the meantime, Lemmy as a platform can benefit from this by fostering a solid community from the refugees that do make their way over. I imagine there's a fair few software engineers who may now be interested in working on this project, which I think will be healthy for things in the long term.
I cant even imagine that Lemmy could handle one million users. But there will probably be ways in the future, after all Mastodon managed it somehow.