For context, I live in Germany and am familiar with the landscape here. Also, I would not equate a 501(c)3 to a gGmbH; gGmbH is more like a B Corp (at least in some of the states that allow it; corporate law differs from state to state in the US). A gemeinnützige Stiftung (Foundation for public purpose) is much closer to a 501c3 than a gGmbH, and a Familienstiftung (Family foundation) is closer to a family trust. (At least for tax purposes, which is the territory I'm most familiar with in this comparison).
But that's not what I'm asking about. Unlike in the US, Stiftungs in Germany (both family and public-purpose) can own an unrestricted percentage of shares -- including all of them -- in normal companies (Kapitalgesellschaften). And I'm specifically interested *not* in restructuring a GmbH as a Stiftung, which is what Ecosia decided against, but rather, I'm wondering if there are any resources available discussing pros and cons of forming a Stiftung as a holding entity, fully owning a GmbH subsidiary (such a construct is not legally possible in the US).
From my perspective, this holding structure would provide much better legal insulation (in both directions) from the founders, preserve the operational flexibility of the (operational) GmbH, while allowing distributions from the GmbH (which would, by definition of being a 100% stakeholder, flow exclusively into the Stiftung) to be distributed by the (purely administrative) Stiftung, according to the founding documents. But I've never seen such an arrangement discussed in depth, which is why I'm asking about it.