I imagine that the less concrete requirements on the UX make it more difficult to negotiate design decisions via pull requests. Typically OSS code contributions

I imagine that the less concrete requirements on the UX make it more difficult to negotiate design decisions via pull requests. Typically OSS code contributions don't include design changes (e.g moving proven core components from shared state to a message queue for aesthetics), but bug fixes or very concrete feature additions which are easy to reduce to tests.