Personaly: already has. In general: I hope not because that would mean I need to close my own instance (and every other instance as well… server cost for Reddit is running in the millions per month!)

It has already replaced reddit for a lot of people. It would be difficult to surpass it, but after all it doesn’t matter how many users a social media has if most of them are lurkers. From what I’ve seen on Lemmy, people are more willing to engage with others. I’m one of those people, in the two years I was on reddit I didn’t make a single comment or post. Maybe it’s because the fediverse is much smaller than reddit and feels more like a community. In that case I wouldn’t hurry to “replace” reddit.

It does, but without r/place

To me it already does. Perhaps some more activity in my subscribed communities and bins but that will come. (mostly about writing, fiction and sci fi)

You mean the Fediverse as a whole, not any one specific platform? In that case yes. But it won’t be just Lemmy.world or even all of the Lemmy instances. It will be all the platforms that use the ActivityPub protocol that in combination will replace Reddit.