You cannot call it a supply chain, if you have zero contractual relationships with the authors of the solutions you are using.
I mean, that’s just arguing over whether or not the definition of “supply” implies “compensation”, which isn’t very interesting imho.
The grandparent’s point remains the same, the software ecosystem and its supply chain or however you want to call it is a hot mess.
So what?
Oh that one really makes you think doesn’t it.