Photos also help against a trick where sellers replace the product name, description and pictures to basically transfer the positive reviews to other products they want to sell and know are garbage. Customer photos make it more obvious at a glance.

And at least for German I can say that fake reviews are probably not more expensive...they seem to just have lower quality and range between barely understandable auto-translation to almost passable if it weren't written like an advertisement.

Sometimes, photos can be paid reviews as well mostly they do it for free products.

Yes, but a picture is worth a thousand words. If the products packaging is highly misleading (making a kiddy pool seem far larger than it is, for example), a picture outside of a photo studio will show this fact quite readily and obviates the need to examine the product in further detail.

I still find photos helpful because they show what the product looks like in real life. How bright is that laptop screen really? An few indoor photos from different people is helpful here.

You have no idea what the exposure settings were on the camera or the amount of available light. It isn't possible to judge screen brightness from uncalibrated imagery.

Photos increase friction for real users but are not a material cost increase to paid/fake reviews.