I wouldn't call them frivolous. Quite a few people believe training generative AI models on their copyrighted work and providing others with access to that model violates their copyright. IANAL but it seems a weak argument to me. And it seems weak to some IP lawyers I know as well.
It also seems like technology that can't be realistically bottled back up. However, I wouldn't call lawsuits frivolous and it might actually be useful to get some legal clarity
I have yet to hear a copyright lawyer who actually understands how these tools work say anything other than that it's going to be fair use; the ones that I have seen comment on it as such seem to have extremely misunderstood how the tech works and how the images are used, they've just regurgitated the arguments that the artists opposed to it make (about how it copy and pasted images, etc).
Maybe I'm wrong, also not a lawyer, but I've heard from enough at this point (including ones that I've paid and are actually our lawyers as we evaluate internal use of the tools) that I definitely wouldn't bet on these suits succeeding.
It also seems like technology that can't be realistically bottled back up. However, I wouldn't call lawsuits frivolous and it might actually be useful to get some legal clarity