Seeing the weights is useless for knowing capabilities, and even knowing training data and architecture you still need to interact with it to figure those out, which you can do with cloud AI just as well.
The real risk that I see is the use of open source AI by governments, corporations and criminal groups to influence elections through a deluge of bots. Cloud AI can at least be controlled to some degree because there is a government that can inspect and regulate that business, but an army of bots built on local LLM’s could just run wild over the internet without stopping them.
How many comments in this thread are written by a bot? I do not feel confident I could tell them apart.