system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do movies made in the 80s (and prior) have visible imperfections, specks, streaks, picture wobble, etc. and new movies don't, even if they're both shot on 35mm film?

I'm judging from Blu-ray transfers.
gpt
Because film degrades over time, and the film has aged. In some cases it’s aged well. In others, not as well. So for films in the 80s, it’s been sitting in a can for 40 years. Ideally in some climate controlled vault. Though that doesn’t always happen. 

It really depends on the condition the film is in when the transfer scans are made to even begin a remaster. 

Not all physical film types hold up to time as well either. 

Other things, like film grain, and special effects masks that wobble, were sometimes present in the original film anyway because back then everything had to be done optically/manually. Ghostbusters is a good example of this. Even the remasters retain the film grain, because it was just a grainy movie.