The idea is to download the “project” down to a local machine, switch to the contributors’ PRs, and have those new files natively show up in their directories. Then they can use local software i.e. Inkscape/Illustrator/etc to edit those SVGs and commit the appropriate changes. This is really not feasible with a forge’s web UI.

The case of free CI/CD, visibility, and network effects are already said. So I wanna offer an anectode: someone I know is a graphic designer, who maintains a project that curate icons. Moving to Codeberg means he has to interact with PRs using the CLI, which he really does not have familiarity with. GitHub OTOH has a simple desktop client that allows natively switching across PRs, approving then in the UI, etc. It’s really, really convenient for someone who’s not a developer.

I think Forgejo-based platforms will need to work on a very good GUI client, in order to attract less technical contributors.