98.css – A design system for building faithful recreations of old UIs

Also worth checking out: https://botoxparty.github.io/XP.css and https://khang-nd.github.io/7.css

In both of these as well as submission link, one of the things that is clearly and strikingly different from modern UI is the lack of very abundant amount of padding space. I think it's almost the mantra that we need breathing room, e.g., between different options in a radio-group box list of items... but I find lesser space (as was characteristic of older UI's) to be more honest... more respectful to me as an end-user, more information-dense.

I don't want to discard whatever innovation has been done, but man I find myself being nostalgic of old UI quite often.

The mouse has significantly higher precision than touch interfaces. That's a large part of why modern hybrid interfaces have such low density.