The Replika AI stuff is definitely concerning because it deprives people of actual relationships by subsituting something artificial that can never supplant something physical/real. Kind of like the movie Her (2013). But this is already happening with stuff like onlyfans.
The stable diffusion stuff shouldn't threaten artists, in the same way that digital art doesn't threaten traditional artists. It's just another tool to be integrated into their workflow. Use it as a starting point to refine, or for inspiration. Did early animators feel threatened by computers? Sure, but it meant they didn't need to hand trace every frame for rotoscoping. Did Phil Tippett feel threatened by CGI superceding his stop motion in Jurassic Park? Probably, but he evolved to integrate his knowledge into the CGI performances. They also ended up using scale models/animatronics for basically motion capture, using elements from stop motion. He still pursues his stop/go motion passion as well.
AI instagram models aren't anymore threatening than current instagram models, since they already set unrealistic expectations based on fake personalities and lives.
Yeah, a problem is people anthropomorphizing it and by doing so they assume it has more intelligence than it actually has. Its an interesting technology, but you're right to be concerned (as am I). I honestly don't think anything can be done to prevent it though, especially as SV companies disregard ethics and want to just produce products without thinking about the repurcussions. Maybe there will be a backlash eventually against AI as people once again strive only for human relationships. Maybe society will be stratified along those lines. The best you can hope for is that people continue to think and question.