I guess one of the things we all have is opinions.
Some are based on solid experience.
Some are based on limited experience.
Some are based on conjecture.
I like to think that opinions I have expressed are based on solid experience.
However, like any of us, I can be biased at times.

I have been blessed to hunt some of the best game country in North America.
I started as a youth, and am now a senior citizen.
In that time, I have shot close to 250 big game animals.
Enough to gather some evidence as to what works well, and what does not.
If, when I open an animal, I find that the bullet has disintegrated, or the core has left the jacket, that bullet will be put on the "practice only" list.
I agree that conventional bullets usually kill deer well. but what if one gets that once in a lifetime opportunity on a real "keeper" and the angle of the shot demands breaking heavier bone to get into the vitals.
Are you certain that cup&core bullet is going to make it in?
If we are talking Grizzly, Elk or Moose, then the problem is magnified considerably.
I reload, and have since 1964. That gives me the option of using a premium bullet in everything I shoot.
I do so by choice, and have yet to be disappointed.
I feel that the extra cost is a small price to pay for the confidence gained.
With the exception of a FMJ, I do not believe there is an expanding bullet made that can guarantee exit every time.
Regards, Eagleye.