Why is little endian used in transaction formatting and other parts of bitcoin?

I’ve noticed just from studying the raw hex values of transactions that many components are formatted in hexidecimal little endian.

For example, the amount specified in an output will be formatted as b6f5050000000000 instead of 0005F5B6, which represents 390,582 satoshi.

To be honest, I have a basic general understanding of big-endian vs little-endian but why is the little-endian format used? And why not just use the normal hex string format like 0005F5B6 in the example above?