This is the fundamentally flawed and misguided argument that can literally be applied to any technological progress to curtail advancement.
Imagine if the medical tricorder (a device from Star Trek that does maybe 99% of what modern doctors do) is suddenly invented today. Doctors could use this argument to defend their livelihoods, but they lose sight of the fact that doctors don’t exist because society needs to employ them. They exist because we have a problem of people getting sick… if more sick people can be helped then great! That is an advancement for society because more lives are saved (as opposed to more doctors being employed), and then simply the standard for what doctors are expected to do is raised to a higher level, since someone is still expected to operate tricorders.
Similarly, artists exist for their output for society. If these AI models can truly fulfill the needs of society that artists currently output (that is debatable), then that simply raises the bar for what artists are expected to output. But it doesn’t change the fact that we only care about the output for society (which can never be truly harmed by advancements such as this because if someone can not outperform the AI then they are redundant), not the fact that artists exist.
Put another way, many current artists who fear this are simply doing the generative work of AI already… manually. The AI is democratizing art so that the lowest hanging fruit of art is now accessible to more people. The bar for art has now been raised so that the expected quality of newer work is to be much higher. Just like how after computer aided design was invented the quality of movie effects, digital game art, etc, all jumped. Progress means those doing current “levels” of art will need to add this tool to their repertoire to build more impressive things. Rent seeking and staying in place (from an artistic advancement point of view) is not the answer.
As someone else put it in a comment here, looking at other works of art and learning how to make art and creating new art from this influence is literally how humans have been doing it for eons. Everyone is standing on the shoulders of giants. This AI merely makes it explicit so I guess it brings out the rent seeking feeling since people must feel it’s now possible to quantify the amount their own work contributed to something. I guess if you don’t want anyone to be influenced by it—AI included—the traditional way is to not show it to anyone.