It's about music.
Old soul, rock, funk etc., bands can keep touring because the music and live performances are worth it. You get a show with some dancing, elite instrumentals and great singing.
What rappers are truly entertaining to see in person compared to any great legacy non-rap act?
Like if Cash Money went on tour in 2000, they'd sell out everything because it's the hottest ticket on Earth with a bunch of new hits. Would people have the same energy 30 years later?
What rappers put on a show like James Brown, Michael Jackson, Prince, Earth Wind & Fire? You can make money touring at your peak because you're the hottest act in the country....but legacy touring is about the quality of the show and people feeling like they'll get their money's worth. It's like someone standing on stage, dropping poetry to a beat. Most people don't want that.