Timbo still got a lot of rap songs with Missy Elliot tho so that's just you picking a bad example
And comparing mainstream artist to underground artists is disingenuous as hell, most of Dillas best beats are recognized as instrumentals which is fine in the underground world but blasphemous in the mainstream world
A general top ranking shows respect to BOTH underground and mainstream, that's why Dilla is there.
If you see DOOM in someone's top list it because in the underground he IS legit top 5, and you can't just blatantly ignore purist underground rap's existence like that. He's the Nas/Jay-Z of that shyt and even those guys would tell you to put respect on his name.
Quick example.
People acknowledge the Harlem Globetrotters.
that ain't because they did anything comparable to NBA players, it's because for the game of basketball as a whole they had just as much impact as a legendary NBA player, you can't just wipe them from history because they weren't in the mainstream basketball league, same with And1 and Hot Sauce, they're the GOATS in those lanes of basketball and any real hooper would show respect to them, you can even see their influence in NBA players
A lot of the producers we put in GOAT lists have given their best work to rappers who aren't exactly elite.
I'm not saying Dilla shouldn't be respected, but when he's placed above Dre, who has shaped careers and created music that defined eras or Larry Smith, or Q Tip, etc.
I mean, people using Slum Village as an example. That's fine, but again, if I used a Timbaland & Magoo album to prop Timbaland, it would be laughed at.
RZA and Premo don't really have mainstream hits like that, but rank highly because they were foundation to the sound of a lot of all time greats or they had their own movements within Hip Hop. Its kind of why I would put Timbaland in a Top 10. The production was so crazy, people bought and listened to a whole album of Magoo. People would check for a Petey Pablo album or Bubba Sparxxx album just for the beats.