They're random from the entire set. There's only about 90 posts at the time of writing. I did disable a few... somebody was very keen to express their love for genitalia lol
What device do you have?
The animations are kind of resource intensive. There are some performance optimisations if the frame rate drops but perhaps it needs to go further
There should definitely be a standard API for this stuff by now allowing browsers to control the cookie experience. Maybe we're moving in that direction, I'm not sure. I think there was a feeling the law would be rolled back so there was no major push to standardise things