Hi,
Several months ago I ran an https-accessible mirror of old drivers removed from Intel website in 2019. Non-profit, no ads or whatever. Just something to give back to the community. Half a gig bandwidth.

I'm not posting the URL, it's not a promo post.

There are just a bunch of directories with drivers and PDF's. I've enabled directory listings in web server config, but those are never indexed by Google, only the PDF's. Almost nobody can find the actual drivers itself.

What exactly did I do wrong? Developing a full-fledged website with ten thousand pages is beyond my abilities, I'm a sysadmin, not webdev.

No restrictions in robots.txt. Wrote a script and generated a large sitemap.xml. I have a google account. They accepted a sitemap. In server logs I see people occasionally reading the documentation but quite few of them are clever enough to remove the filename part of the URL to visit a directory and download an actual driver.