Different types of reptiles have different husbandry requirements. With ball pythons UTH is a must. The heat lamp is optional. I chose to do both as a way to not only regulate the hot spot (UTH+thermostat) but also help with the ambient temperature over all (lamp + dimmer) plus I like he badass red light the lamp gives me
As people have mentioned BPs need belly heat to digest and stay healthy and properly warmed up. Also as cold blooded creatures they rely on the temperature of their environment to thermoregulate so it’s important for them to be able to cool down or warm up as needed.