My battery is at 69% (which I'll get confirmed today by Apple when doing a battery swap) and when it's throttling aggressively I literally can't take a photo in the stock photo app, it just crashes. I was in a life and death emergency situation and I almost couldn't text my family as needed to keep them in the loop. It's absolutely an issue with negative real world effects.
Same here, but I could have used the throttle to keep my family safe.
Last year, my iPhone 6, original owner, updated iOS, went skiing with the family in 20 degree weather. I've got teens, they were on their own all over the mountain. We decided I would text them all in the afternoon and we'd all regroup, grab some lunch, make sure everyone is accounted for and okay.
So 1PM arrives, I take my iPhone out of my pocket, and it's dead, it's got that charging cable graphic up and won't respond at all. Home button, hard reboot, nothing is working, the thing is not responsive. My wife's iPhone 6, same thing. Turns out all 5 of our iPhone 6's with 100% battery were all on the same screen, all dead.
Fortunately we all had the same sense of what was going on and we all wound up at the lodge by 2PM. Once the phones were inside in the warm air they started to respond.
If Apple had instituted this new protocol for throttling the phones, last year we all would have had working phones on the mountain and never would have been out of touch with each other. So while you may not appreciate the slowdown in certain situations I can tell you I would have welcomed it in that situation, quite upsetting for a father and mother to not be able to reach their kids for a lengthy period of time.