They are open source in the way Android is open source. The actual results are open source indeed, but the culture and the chain isn't, so, if the people who run the projects decide that they are not open anymore, they won't be. And so, the projects will stop, as there will be nobody to release the newer versions. Same as how Android could maybe maintained indefinitely, but not improved in a way that it is right now.
All competitive open models today share a common property; someone spent a large amount of money to train them and then released the model for free.
I don't understand why the argument continues to be we will have a rich ecosystem of base open source models; unlike opensource ai which is individuals donating time, opensource ai requires someone to donate very large amounts of capital.