I do think AI fliers, aside from being a function of being lazy and cheap, are partially a byproduct of there not just being an agreed upon, free, good alternative to Photoshop.
Anything that COULD have been a decent alternative is cram jammed full of "just generate it bb✨" shit too! Canva looked like it was gonna come for Illustrator / become the next "ah yes you used template #4" alternative and then they went deeeeeep into genAI and I think that's sad