Not really, here is an example of what I mean by compression.
This picture is taken from the op and has about 1,8 MB
View attachment 3639767
The same image compressed in .webp format has 52KB !
Can you see a difference? I guess not and if they did that with every graphic, the whole game would probably be a lot smaller. There are also other compressions like the AVIF format which are maybe better in quality.
Edit: I don't know why F95zone can't show webp images, so just open it in a new tab your browser should display it as image.