TBH, greatly reducing the overhead of the process of acquiring clients is what sells me on the idea. As a consultant/freelancer, you bill a high hourly rate to make up for a lot of this overhead. A solid market for projects means more profit.
I think the ability to take on larger projects is great because the projects are likely to be more interesting, without being overwhelming.
FWIW, I'm a product manager and front-end developer at my own startup and on GroupTalent I'm working as a product manager with a development and design team in Colombia.
I found out about GroupTalent from the development team. I had worked with them before as a client and liaison between our development team and theirs, so when I reached out to them we knew it was a good fit between us.