Ya i think people can't separate compression artefacts from what could be photo editing.
Higher resolution is absolutely required to make any determination about editing - but you can zoom in on any 200kb jpg and the muddiness and little squares will make it easy for shit to look "off" to the layman.
The Face on Mars is a perfect example of this: the face was only there in the earliest photos, high resolution showed everyone the face was just a product of a low res image and the confirmation bias of a fantasist.
Low res to high res face:
Uh, the face is still there. It's just scarred now by all of the hate.