Lauryn was definitely the biggest Hip Hop artist that year. I get that there's a lot of singing on Miseducation of Lauryn Hill, but there's emceeing on that album too and its not just passable for a female rapper emceeing, but she was really spittin on that album. And I know people will still try to paint that album as a "safe" choice because of all the singing. Still, Miseducation was unlike any other album in Hip Hop or R&B at the time and the closest thing to it was Missy's debut, but the rapping nor the singing on Missy's Supa Dupa Fly was anywhere near what Lauryn was doing on Miseducation. Miseducation was exponentially more successful as well in an era where Kim and Foxy still reigned.
You posed the question of when was the last time a Black artist topped the charts and won awards, but backhanded Lauryn Hill. Lauryn Hill debuted at #1 and set a record for females for first week sales in 1998. Before her, there was no female who sold 400K in one week, Black or white. Let that marinate.