30 years after I gave up the Rollei, I'm not obsolete as a photographer, and when there's a quality diffusion model that could take a few of my photos from the event at 100 megapixels, and get prompted by me as to what I want to see out of them creatively, I will still not be obsolete, even as a photographer, but most certainly not obsolete as an artist. In fact, I'll have more tools available for my art, with new skills needed, and different workflows.
As to abandoning 3D art -- your call. If you love it, why not see how these new tools open up your art? If you don't love some of the new tools, no problem, don't use them. I still shoot medium format film some times. If you were planning on a long term creative career without staying on top of technical advances in your field, that has not been possible for at least a few centuries.
Are legitimate companies genuinely switching to Midjourney over hiring artists now, or is Midjourney usage still mostly happening in places that previously wouldn't have commissioned custom illustrations at all (instead using things like stock photography)?
There're hundreds of thousands of '3D worker' working behind the scene to create the 3D models for makeshift ads, and as far as I know many of them (including my high school mate) already got displaced by Midjourney and lost their job. This used to be a big industry but now almost entirely wiped out by AI.
To my knowledge, 3D artists weren't that huge of an industry to begin with. One of my friends went to college researching 3D physics models, and never landed a job in the field long before the AI wave hit. Unless you're a freelancer or salaried Pixar employee, being a 3D artist is extremely difficult with extraordinarily low job security, AI or no AI.
I think "almost entirely wiped out by AI" is hyperbole, because the primary employer of these artists will still be hiring and products like Sora are a good decade away from being Toy Story quality. AI will be a substitute product for people that didn't even want 3D art in the first place.