Monitor vs. Beardie basking temps?

[boosh96]

Here's something I don't understand-why is it that bearded dragons, who live in the Australian desert, require a basking spot that's only, like, 100-110 degrees? I can see why monitors are generally said to need a basking spot that's 130-150, since I understand that's what their basking temps are like in the wild, but why don't bearded dragons require a similar temperature in captivity?