also, you had groups and artists around his time who could spit so much better than him. look at artists like the roots, a tribe called quest, the pharcyde, big pun, a.z, outkast, de la soul, jeru the damaja, nas, big l, leaders of the new school, heiroglyphics/souls of mischief, mic geronimo, d.i.t.c, the fugees, redman, gang starr, black moon, aceyalone, WU-TANG (plus affiliates like sunz of man), onyx, mobb deep, pete rock and cl smooth, jay-z, main source. any of these shit all over pac.
edit: also charizma and peanut butter wolf, easily the most underrated duo of all time.