Let's analyze it.

Reddit is declining in a way liberals can't deny. The more ideological among these liberals attempt to leave, but without theory, without knowledge of Marxism, or even Anarchism, without a firm understanding of Historical and Dialectical Materialism, their world view is framed in a manner that casts Capitalism as bad, in an almost Ultraleftist manner, but Red Scare propaganda still makes Marxism spooky.

They occupy a space that considers Capitalist countries with pure nuance and critical support, but only judge leftist movements as though they are Ultras, and nothing is satisfactory.

From there, Liberals seek a replacement, and further still they don't quite accept federation, so they go to the largest generalist instance. This is Lemmy.world, so they get to have a space filled with ex-redditors kicked out by Capitalism's failings, but unwilling to embrace any actual alternative, occupying a weird middle ground.

Therefore, Lemmy.world appeals to radical, theoryless liberals, with no specific or niche interests, and creates an echo-chamber around that specific anti-specificity.

Just my 2 cents.

Dialectically, I believe eventually .world will defed from .ml, or vice-versa, from some unimportant inciting incident, creating a multi-polar Lemmy, so to speak, but that's a bit odd to say directly to you. Either way, I see a contradiction that appears to be growing, so Dialectically there will likely be a shift from the quantitative to qualitative, so to speak.