IMO, Partitions were design during a time of lower velocity cartridges. It worked well. Then the high velocity cartridges came along. Monolithic, bonded lead, etc came along. Manufacturers found ways to strengthen the bullet integrity.
Nosler Partitions still have a place, IMO, in slower say 30-06 velocities. That’s where I primarily use them, or on more delicate game such as antelope where the animal is thinner and needs quick expansion.
Admittedly I used a 300 WM with 180 NP bullets on my first PG trip. I wasn’t satisfied with their performance particularly on tougher animals such as blue wildebeest and zebra. They got the job done, but nothing comparable to my 375 H&H with monolithics.
Much less penetration at closer ranges seemed the main issue with the high velocity Partitions. I didn’t lose an animal, but the zebra took multiple shots after the first hit bone and didn’t penetrate.
When you pay for for blood vs animal down, you want the best you can get. JMO&E