Disagree.
If you are posting to an art site (and that is what this part of F95 is) in anything over 1080p then PNG all the way. If you consider this site just a repository for low resolution images then you can have your 50-80% JPEGs. With respect to telling the difference, if it is low resolution, then you are 100% correct, but some people here post higher resolution images and they shouldn't be forced to deal with compression artifacts, just because it loads the images for you and 499 others too slow! I can tell you one thing for sure, if F95 decided that they wanted to recompress all the images uploaded to lossy jpeg, there would be a lot of people doing higher resolution stuff posting their work elsewhere.
We are all spoiled by wanting to have everything right now, instantly. Even with crappy interent speeds this is much faster than using the old usenet channels and 300 baud dial up modems to download single images that took hours to download. An THAT is exactly the set up I started with.
it isn't about everything right now, it is about 99.999999999% of people that will never ever see the difference between your 14mb png and 300kb jpeg of the same image, here are couple of your images to show what I mean:
the "falling over" girl image - that is one where you can actually see some issues, it is in halftones, and not because it is a jpeg problem, it is because you chose to light it in a way that makes those surfaces look all flat and boring, there are no shadows to speak of that would break up the halftones in the 8bit version of that picture
the second picture of the girl on the bench - I guarantee - you yourself would never tell the difference if you were presented with both images even on a very good computer screen, and it is because there are no low graduation halftone changes where jpeg might struggle, we should have been talking about how poor the lighting is in that picture instead of compression
on top of that, speaking of technical things, since you started with jpeg compression, it is compressed in 8x8 (low compression) or "16x16" grids (more compression, subsampling), so the higher the resolution of your image is, the less the actual loss of quality ends up being if you don't chose very high compression
and don't be silly - "I'll go elsewhere", that is pure narcissism, again - 99.9999999999999% won't see the difference, make better comp and light your render better so you don't have to expose the 8bit halftone shortcomings and don't chose 30% quality when saving your art and everyone will be much better off, because 14mb png like these are a waste of resources
first spoiler is your 2 images in original png and jpeg for comparison, size difference is TEN-fold for the hallway girl for a maybe 1% loss of quality
edit: sorry, the hallway girl png vs jpg size difference is actually 65-fold, not 10-fold
and the second spoiler is about what we should be discussing here instead of ridiculous 15mb pngs
and this is how I would fix the 8bit and compression issues in the first one, introduce higher gradient, so there is higher degree of change in halftones and artifacts aren't noticeable any more, also introduce higher contrast between the subject and the background to make her pop
as for the dark skinned girl, they are difficult to make them pop, so a little help was provided, S curve and a bit of dodge and burn, on top of that bench color choice is bad, which I didn't change, just desaturated it somewhat so it doesn't scream in my face LOOK-AT-ME-I-AM-HERE, more neutral or cooler color would be preferable IMO, bleached wood look, to help the dark skin - which is similar color to the bench, so you're sabotaging it already, and removed toes sticking out of the shoe
disclaimer: I never studied arts, and I'm no teacher, this is only personal opinion, so feel free to discard anything I say and tell me to go f... myself if you don't agree
