I don't know if it's in System Preferences, but for me, System Information shows my mid-2015 MBP (running macOS 10.14.6 Mojave) still has a battery capacity of 8266mAh and a remaining charge of 8079mAh at 100%. Compared to the advertised capacity at launch of 8755mAh, that's a charge capacity of ~92% after ~five years (AppleCare replaced my battery during their recall). MacBooks are just built different.