I’ve shot decades with lead, in most calibres and chamberings. I found over the years that lead can also underperform - example, lapua mega 156g in 6.5x55 on roe..about the worst I’ve ever seen in terms of runners! And many many more examples of soft points that were too frangible, etc. all about matching the bullet design and weight, to the intended game target and distance (velocity), as well as the POA the hunter opts for. The perfect round for situation X, but with neck POA, may be a poor choice for the same situation but POA shoulder.
Same goes with non toxic, and whilst I don’t have decades of experience with non toxic, I have been experimenting with many makes and weights and designs for the last 5-7 years or so, and, i do shoot a fair number of deer from Roe to Red.
One thing I can say, and you may not like this - in my experience with non toxic that’s been picked for purpose, and placed where it should, beasts take substantially longer to die, more pencils, more runners, and more needing follow up shots. Not ALL, but MORE, a lot more. So experimenting with shot placement as well, using the High Shoulder and Hilar shot, ‘had’ helped, but the non toxics are still not doing the same level of quick death work that say, the Nosler Partition did.
Many may disagree, but whilst I use non toxic and don’t eat lead shot game, I am open enough to admit I am not a fan of the terminal performance in comparison to lead based ammo.