Super BLACK SEO Tools combination - explanation needed

Hi.
I’m looking for an explanation of how a certain site manages to rank incredibly high, specifically, what "black hat" SEO methods were used.
Not sure if i can share the URL? So let me try to explain at first:

The domain was definitely purchased, and the niche is somewhat related, but the site is currently selling illegal products. (Ahrefs DR previously were around 45-55, right now it stays under 25)
Bots don't detect the redirects;
Built using simple HTML and includes JavaScript that likely hides the redirect from bots.
The entire site is very simple but packed with sales-oriented keywords and products. Each product links to a simple .html file that redirects to the other online store.

Can anyone explain how a site like this works? What exactly is causing it to rank so high under very difficult keywords?

From my experience, sites like this usually benefit from the authority of an aged domain, a strong backlink profile, and content that's closely aligned with the target keywords. If search engines and users are being shown different pages, it could involve cloaking or some type of hidden redirect, but it's hard to say for sure without analyzing the site directly. More often than not, the domain's existing authority is what gives it the biggest ranking advantage.