@Juliencolomb just shared a link to Business Models for Open Source Hardware Repositories in the thread: Publishing hardware: grant for an expert gathering?
I thought it was an interesting article by @jpearce I wanted to discuss without derailing that thread on a gathering. So here is that discussion.
I think there is yet another business model which is possibly harder to bootstrap without large investment, but possibly easier to sustain if it gained traction: Providing hardware repositories that support open or proprietary hardware collaboration. Collaboration on hardware is a hellscape even in the proprietary world, with eyewatering costs for simple version control, and centrally hosted data that make inter-company collaboration tough. Following a GitHub/GitLab model of use is free for open source or very small scale proprietary projects, its paid for for proprietary projects is a very clear business model. It also has the benefit of not trying to have separate tooling and hosting for open/proprietary hardware, where we will always have lower investment.
GitLab for hardware is something I think that could be pitched to venture capitalists. I think that it could make a lot of money if it was done well.