Interesting conversation for sure, I know I don't always like those covers or samples, from the late 90's or 2000's but I fukk with some of them. Tory Lanez came in the game doing that. I liked all that. The Khaled ones were usually wack to me.
Maybe this is a fair point, a lot of the iconic sampling done in the 90's, weren't actually rap records, likely because there weren't that many to draw from, the genre was brand new, the 2010's and 2020's are the first years where producers, who are probably about 25 years old, have a good 20 years to pull from.
Think of songs like
I'll Be Missing You
The City Is Mine
Been Around the World
I'll Be
Hard Knock Life
Feel So Good
All Eyez On Me
Street Dreams
Sunshine
The Message
some of those are R&B samples for sure. but, those are like 80's pop hits mostly. Sting and shyt. David Bowie. Broadway musical.