I believe it can be done, however it would indeed take time and carful thought.
For example, if I would like to work with you, then momentarily see now other way as to give you an assignment and let you make an invoice. You would have to be a freelancer just like me, and capable of making invoices. I would be full owner of the product in this case (which is not what I really want). So I don't see this as an option, I would also have to pay your ours spend (wish is going to be way to mush money for me). The other option (currently also a problem) is that I would pay you royalty's for every copy sold (you would also need to be a freelancer). This would al make administration and tracking many objects very difficult for me, so I don't see how I can make this work. Also you cannot track how many copy's I would have sold, so that is also a problem.
The way I see it, is that this special extended framework for collaborative works would automatically track all these things for everyone involved. So when we have made a collaborative product the money would get automatically split on every copy sold over all stakeholders. Unified income would come from this and that is manageable in my administration. Managing costs of software and hardware is enough for me, managing dozens of royalty's and invoices from assignments is not something I aspire.
There are allot of difficulties to overcome until a collaborative framework could work. For example some tasks would have to be standardized and translate to a % of profit margin/ownership rights. Maybe something like 20% for design ownership, 20% on 3D modeling ownership, 20% on texturing and rendering (10% for texturing and 10% for rendering if separate). So when one designs + models + renders, he would have 50% ownership/profit margin, the more task you do on your own the more ownership, the less you do (for example only make texture cords) the less ownership/profit margin. Only doing texture cords would correspond roughly to something like 5% ownership (just an example).
These things would all need to be figured out carefully and made into a standard working profile for collaborative 3D modeling projects. Custom profiles would also have to be an option if some people decide to split margins differently or ad extra margins for other types of projects.
There also need to be build in failsafe options.
Take for example someone designs + models and a separate UV man does a lousy job and the separate texture painter cannot perform a good job because of it, hoe would lose his margin here? Hoe would have the last say in a possible conflict? (the one with the largest ownership/profit margin or some third party?)
And so one and so forts......
However I see great potential in a collaborative platform, there are allot of human resources not being used to its fullest potential (lots of unemployed artist and talents). The working conditions in large facilities are also sometimes very hard and there are limited spots available. Being able to work from the comfort of the home and self regulating would make allot of sense for allot of artist out there.
Also there are allot of artist in search for likeminded people looking for artistic freedom and expression and in the light of a coming age of massive digital consumption (VR worlds and accompanying virtual items). There will be lots of potential/opportunities to create vast open worlds where one can express all sorts of artistic creation and visionary things.
I believe web services like this one will play an important role in that story, the foundations are here. The framework only needs to be extended to incorporate collaborative project capabilities and crowd funding so that projects can be managed by groups of artist themselves and not some institutional things messing up the place, and sow allowing for concept artist, art directors, 3D modelers, story tellers, music composers, programmers, 3D scanners, motion capturers, game engine developers, basically all creative minds involved, to join in on the projects they want to make.
Sooner or later this sort of platform will immerge, because there is demand for it and it would streamline the use of available human resources (now being untapped or dormant).