I think the general point stands when considering large-scale platforms.
So it's not unreasonable to say that when demographics of forums was changed, the economic incentive appeared? So it actually depends on demographics?
Either or both, depending on the SYSOP's resources. I ran a BBS that did store-and-forward between the U.S. and Europe.
The ones with global connections could take a day to a week to forward messages, but that turned out to be a feature. We went outside in the real world instead of staying online arguing with strangers.