Ever moving, right? People in the top 0.9% all call themselves middle class, maybe "upper middle class" to shut down any contradictions. That's because there's a stigma to being a rich fatcat. For more complicated reasons, politicians like to sweep up most of the bottom 50% that owns basically nothing, as well. The only people who consistently get stuck into the lower class are basically people so powerless they might as well be a thing.

That being said, do be careful that income distribution is quite different from wealth distribution.

Lemmy tends rich and educated. So it would be my guess more than 50% are in the top 19%. Probably by both, since it seems to tend older than Reddit did. What you call that is another matter entirely; wealth and income levels all flow together smoothly in the raw data.