At distance I'd say ya, they are necessary. I shot a kudu cow with a Hornady GMX 150gr,frontal shot, bullet excited out ribs and animal expired within metres.

A friend then shot one with a pmp brown box 180gr soft point, broke the right front leg and the bullet broke up into pieces. Shot placement was a little low, no vitals struck, but the animal dropped on the spot. Why it died we don't know, heart attack from temporary wound cavity?

So if the shot is less than ideal rather have a bullet that won't break up on impact. Even though still died.