What does this mean built in dynamic hardware and software measures? I don’t want my performance hampered. Phone stays plugged in

I don’t want my performance hampered. I see the second box on the battery health section. Your performance magically may be cut back making your phone basically useless and slow to somehow mitigate battery wearing. I don’t want this as my phone stays plugged in. It’s very important I have its peak performance as I purchased it for that reason. I’m not worried about the battery being degraded I would like this setting disabled or something that we can check on or off. It says it’s automatic and always on. This is a problem. I just paid to have a new battery put in when the time is right in the meantime I want my phone running at 100% as that’s why I purchase an iPhone. I don’t want to have to go back to android but I will if I have to thank you guys so much