I agree but i will say 2pac, the jacka,soulja slim,pun, jmj and biggie are the only exceptions to this due to:
2pac- had multiple platinum albums and sucessful movies but unfortunatly him being incarcerated through most of his career then murdered while he was on top of the rap game robbed us of what coulda been, killumimati was a bittersweet glimpse of that.
Biggie: after pacs death rap shifted back to nyc, nas was king of the city with IWW selling 3xplatinum, biggie was looking to get his spot back hypnotize drops february of 97 and all about the benjamins drops on the radio as well with the release of LAD less than a month away hype around it is crazy, unfortunatly he gets killed 2 weeks before the album drops. He was slates to appear on a bunch remixes that summer namely, honey remix, tony remix, a song with terror squad, songs with camron,lil cease album, commission etc.
Soulja Slim: though i think he wouldnt have lived pass 2005, '04 was gonna be his yr with slow motion and noila clap (he was originally to appear on this) he was already hailed as the "2pac" of the south before his death, he was also in talks of working with g unit had all this came into fruition with his polarizing influence on lil wayne, bg,juvenile,lil boosie and others no doubt hurricane jeezy in 05 was happenin regardless, slim woulda definitly been where gucci is for sure with his influence on the game today(kodak black,face tats).
Jmj- no explanation needed.
Big pun-first 2xplatinum and grammy nominated latin artist, surpassed big in most guest appearances in 99 alone and his star was just growing brighter.