Why create low res versions of modern videos?

I have seen this several times lately and wondered why.
People are creating low res versions of modern videos (last 1-2 years and in last few months) and I wonder why this is.

I am talking of 640x360 for example, for one of the Evil Angel videos.

Does anyone know why this would be done?

I also don't get it. Maybe it's meant as a sort of preview. You can check the scene out with a few hundreds of megabytes, before downloading a video with four or five gibabytes load. But if they don't publish the big video too, the little one doesn't make sense.

POPULAR PORNSTARS VIDEOS is getting really annoying because of the ammount of low res scenes that is published there. Can you please stop? It's just a waste of time browsing through the forums just to see the 10th or 20th low res video in a row.

It's not preview but for people with a slow internet access, as not everyone has broadband internet.

Also, but that may be another topic, I noticed a big stepping down in the resolution of Met-Art photosets.
10-15 years ago, they published very large photosets from 800Mb to 1Gb sized, but now the high-resolution is often under 100Mb...

purvert wrote:
Fully agree. This is a worldwide forum and where I live the average time needed to download 1gb is about 3 hours which makes it impossible to consider anything over 2gb

In that case I wonder why more and more videos are in 4k only on this page?

I have to go more and more often to other formums and blogs to find the scenes I'm looking for in 720p or 1080p.