The groups forming the roots of digital media piracy established 'the scene', which holds itself to rules and has particular distribution methods. For example Usenet was popular for many years. https://scenerules.org/

By P2P I'm meaning these are 'non-scene' releases, just something a random person on the internet cooked up and released somewhere, in these cases by feeding some prior standard definition release through an upscaler and creating a torrent from the output, which involves certain considerations.

We can't exactly determine the pedigree of these files, but we can say they are lossy transcodes, that is they first existed in a compressed format and later were re-encoded by the upscaler to another compressed format.

While the upscaled may look sharper to your eyes, data from the files as they were before that process was inevitably lost due to this transcoding. If we define "quality" as the amount of information from the original presentation that was retained in the output, then the standard definition versions are definitely higher in quality than the upscaled ones.

I'm not meaning to use the term in any perjorative sense, but it's useful information to have. If an official HD presentation is ever made from the original film, it would certainly get a 'scene release' that would look better than these ones.