This is dense. I skimmed through hoping to see examples of the “aesthetics” with screenshots of old school installers (like the ones from Razor 1911, Class, Deviance etc) - it looks like these are scattered around the web, though. If anyone wants to relive some of the old chiptunes from these installers there’s https://archive.org/details/codex-installer-music-5-2018-03-...
Be sure to check out keygen music, still updated
Some of the chiptune musicians are still active. Dubmood made it onto the Hotline Miami (2012) soundtrack.
Razor 1911! Now here’s a name I haven’t heard in a long time, but teenage me was very grateful to.
The .nfo files alone, distributed with most releases, carrying the most elaborate of ASCII art. I distinctly remember the aesthetics you mention.