I feel like that's kind of an apples-and-oranges comparison, given that Second Life's going to have a, by comparison, massive lean towards well-off older adults

I feel like that's kind of an apples-and-oranges comparison, given that Second Life's going to have a, by comparison, massive lean towards well-off older adults with long-term investment in the SL social ecosystem. If anything I would look at VRChat for comparisons instead (a young demographic, especially on standalone headsets, and an ecosystem that's still very Wild West in many ways), though measuring numbers there would be much, much harder since most of the creator ecosystem happens outside of the app itself on Gumroad, Booth, etc (content subscriptions through VRChat itself are still only in beta).