I read your other post just yesterday and it reminded me that 500px has an agreement with Getty for stock, so I uploaded some more images to see how they'll go. I'm kind of unsure what purpose purchasers would use landscape/nature images for. Is it mainly advertising or editorial use?
I'm not sure how well the 500px licencing goes, even with Getty. Although I can't see exactly what my photos will be used for, you can google search them to find if they are used on websites, which most often is editorial or some banner image.
I once was sitting in an airport waiting for my wife to arrive when I saw my photo come up on a big ad screen for Qantas/Avis. Another time just scrolling through Instagram and a sponsored ad for Telstra came up with my photo (photoshopped with people in it and a different sunset).
So they are out there in some form or another.
Stock images just need to be commercially viable. Clean and generic and maybe even stereotypical for a location would do well. Just look at the first image in the above collage. It could be used for anything "Vacation", "Tropical", "Relaxing", "Retirement", "Luxury" etc. It doesn't just have to represent that specific beach in Western Australia.