From my pov and recollection of how this evolved, that's by intent. The early drafts really had non-commercial (contributor) or manufacturer. Then at the last minute to try and capture the cases represented by the oss foundations and other tooling like Github or Maven Central, the steward was created. So for me, I wouldn't expect a project to fit into that steward category. What's not clear even to me though is where the line is between a single project and hundreds of projects where a steward comes in to play.
I believe this because the legislation basically just says the steward has no fine. The requirements seem to be essentially the same as those of a manufacturer but without the teeth.
Stewards are under a light touch regime which is considerably lighter than the manufacturers. They're not subject to the obligations of Article 13 and only partially to those of Article 14.
--tobie
For the decentralized work on a project: please watch Benjamin's presentation from 23:20. He makes it clear that if there's no steward and there's decentralized development (possibly many manufacturers including that software in their product), this is "no-role" under the CRA (out of scope):
https://www.youtube.com/watch?v=oVTO6s7eMLk&t=1421s
Also, there's his description of the steward role and who qualifies in the minutes before.
