In your example, the launcher would be open source but the blob would not. When you look at the proportions of the code in the combined software, it would be obvious that the majority of the code is proprietary and that the software as a whole is mostly closed source.
Like the SaaS apps which are touted as "open source" with small open source clients which are not functional without the closed source backends (or with open source backends which you can't install because of a couple of non-intentionally missing important bits)?
Or like Nvidia's new drivers which are "open source", but all the meaningful parts are either buried in the card or in closed source libraries?
Or like VSCode where the plugins which matter are closed source and it's "open source sibling" VSCodium is banned from using the majority of the plugins?
If the 99.9999% of the tool is open source, but non-functional without that closed bits, can we say the software is open source?
The four freedoms matter, and this is what OSI says, too.
We're in full agreement here. It's dishonest to describe software as open source when it is not operational without key components that the developer intentionally made closed source. I would be fine with them saying that the software is "partially open source" and explaining up front exactly which parts of the software are open and which are closed. As a whole, if a piece of software is non-functional without a proprietary component, then it is not open source.
