I learned a concept from SA. That concept is ignition. Ignition is the point where an economy or community becomes self-sustaining, and new people need only plug into it with a specific small innovation. Living in The Metaverse asks why more people aren't on Open Sim.
The answer, I feign (I was thinking of that word in the shower as the soap oozed over my nipples and down my front. BTW guys, if you have a girl coming up to visit you... make sure you have her favorite toiletries, they are confiscating anything liquid at the airport for all practical purposes... Dial soap. Blech...) is that Second Life's economy is at ignition. The reason not to go to OpenSim is that development doesn't work very well, the price for building is as high as it is in SL, and the tools are more primitive.
I'm going to say that most of the content industry on SL is doomed, because it is the result of a temporary problem of tools. The tools for making content in SL are not good, and they don't carry anyplace else. When the tools get better, while many current designers are fabulously talented and will still make and sell great things, there will be many more people who right now just don't think it is worth the time to learn a woogely UV map and fiddle with joins by hand. When standard tools upload in standard ways, then the price of content is going to shift radically. OpenSim needs to realize that what it needs is not just an Open Sim, but the basic content engine.
Now to get people to work without a direct payment system, you need to give them something else. Like the chance at making money later, or fame, or sex. OpenSim, if it wants to ignite, needs to make it possible to do that. Right now, at the price, it's not compelling.
Want ignition in a gift economy? Make it so that the content has follow on use out here in the real world.