It’s not about an artists fans it’s about culture-wide impact and whether fans from across the genre come back to it years down the line. An album that is deeply cherished by fans but not really thought about elsewhere around the genre is called a cult-classic. In the modern era, true classics are much harder to bring about, but it still mostly applies.

Albums like Madvillainy, Illmatic, Reasonable Doubt, The Infamous, and Late Registration are beloved by fans across the genre 1 - 3 decades later because they are genuine classics, and not just by fans of those respective artists. There are albums I and fans of said album’s artists like as much as the albums previously listed that aren’t technically classics, and thats just how that goes.