Well that's never good when the company is not transparent. I looked into Midjourney and noticed while they are most likely stealing the art of others online, they own the copyright of all the images made on their platform (even paid users, you get to keep yours but they own a copy). I'm guessing this is how they plan to shirk copyright lawsuits. Eventually they will have enough images made by users that are 3rd, 4th, 5th, generation of the original that they'll get to keep them. It will continue to be in legal gray area regarding copyright for some time.
It's certainly won't be the death of art, it's debatable whether it is art since the machine is simply throwing together existing art and shaking it around, then spitting out new image. If it is art, it's he Las Vegas of art. I don't have enough information to come down firmly on anything else about it. I can see how it could be useful, but I can also see how exploitative it is to the original artists. Artists are already not compensated enough for their time and expertise (in the US).