Anything taken before 2023, yes. I had a former colleague who's boyfriend was a photographer, and he took a shitload of pictures of her in various random business suites and situations, close-ups of her holding pens, mugs, papers, glasses, etc. etc. and published them on some stock portals. They don't pay a whole lot of royalties for multiple use images, but every now and then someone buys an exclusive license, meaning the picture is afterwards removed from the stock archive, and that pays several hundred bucks.
So it's really a numbers game, the more photos you dump on the platform, the better.
Anything published since last year has at least a chance to be AI generated. Should be tagged as such, but well. Should.
I was chatting with a stock photographer a while back. Apparently the most important thing is the tags that you give the photos. The best ones are abstract because you aren't competing with "hand" and "pen". If you can make your photo of a hand holding a pen fit "wistful" or "trenchant" then you have a better chance of it being seen. Making thousands of weird photos like a hammer/screwdriver/wand being held over a watermelon/plastic duck/brick by a clown/policeman/nurse and giving them abstract tags is the way to go.
Even without AI there's an awful lot of random stock photos. Years ago I remember I searched for and found a stock image of a woman tied to the train tracks of one of those kids mini train things, also there was like a few to pick from. I swear it was in some way relevant to the presentation that was giving but they can't remember details.
Bonus question, was being a stock photo model a "full time job" or it was more an actor/model job that you do between more interesting projects ?
That said, with the ridiculous price of stock photo, and the remaining glitches in AI model, not sure whether it's really cheaper to generate an AI image (Need to get high resolution image, and to review them, you don't want a bad buzz because a necklace didn't close or whatever glitches are left) . It's basically depending whether some stock photo bank have implemented a natural language search.
I'm not certain if it's a full-time position, but I'm aware there are part-time model agencies that hand out odd jobs here and there. The ones I've come across were for clothing catalogues and so on, but I imagine they exist for stock photos too.
Don't know if it's a full time job, but I work with stock photos for a range of clients, and there are some people you see pop up in dozens of pics, covering all sorts of differing scenarios. There's one particular older woman, with very short white hair, who I've seen over and over and over again, it's weird.