I think nobody is concerned about this because most campaigns just deliver what they promised.

Etsy used to be awesome, now it isn't. Lots of mass-produced junk played off as quality made-with-care-and-attention kinda stuff. It's even easier with AI images, videos, description and communications.

I think kickstarter is gonna have (or maybe already has?) a scam problem due to the rise of AI.

I've contributed to about 7 campaigns; only one didn't work out. But the person running it actually refunded me fully (about 200$) after 3 or 4 years of very occasional updates.