It depends on the caliber. With 357 mag, it is hard for a bullet NOT to be effective. Just about any 125 - 158 grain hollowpoint with 500-600 ft-lb of energy is going to have good terminal performance.
Same is true for 10mm. And 44 mag, hot 45 LC (as noted above) and probably 45 ACP+P as well. I don't see how advanced bullet technology is needed with a 200 grain (or heavier) projectile with 500 ft-lb (or more, or a lot more) of energy.
Now if we are talking about 38 spcl, or 380, then yes, I think bullet technology can make important improvements. Look at how far the 9mm has come... 30 years ago, 9mm hollowpoints were marginal. Now their terminal performance has been greatly improved.