Yes, it's called progress. Some jobs will disappear but others jobs will replace those. The world population is quite bigger then what it was 100 years ago and even thought computers and robots replaced a lot of jobs we still have jobs today as a matter of fact we have more jobs. As someone has to mention and program those robots. Someone has to create programs and games, someone has to mentain the infrastructure. Youtube videos and streaming became a job. Simply put the point I'm trying to make is AI might take away some jobs but it will also open up new jobs opportunities for other people. And no matter how pissed of you are that AI is doing something that you consider wrong and think that only humans should do it you will never be able to stop AI from becoming a thing. There was a lot of push back against automatisation too and that did absolutely nothing and humans got replaced by robots on assembly lines and shit like that.
And no I don't assume that it will stall, it will evolve but humans will still have to give inputs to AI in order to crate those posters, and we will find more creative ways to give better inputs in order to get better art. Simply put using AI at a professional level will become a skill and a new job. I'm pretty sure that I wouldn't be able to create better AI art the someone that does that everyday as a job. At best I will give some input like make this picture in the style of Picasso or something while someone that studied art will know more art terms and concepts then just make it like Picasso.