Indigenous peoples killed big game with rocks and stone tipped spears, not always with great success and sometimes hazardous to the hunter.
Why would one use a spear or .30-30 for large game animals when far better implements are more effective and available? Asking for a friend….
Because a 30-30 just plain works. I've seen 30-06's not exit a deer, never seen a 30-30 not exit
The bullet construction works exceedingly well at 30-30 velocities