Why is data in all databases stored in HEX?

Question

Database

Parsing the structure of the database, I still could not understand - why do all databases store data in hex without exception? (screenshot below) From the largest databases to the simplest
After all, with each request, resources are spent on constant recoding and hex (according to my personal calculations) weighs 2 times more

Thank you

Answer 1

No, they don't. Show some types of data - can.
For example, MS SQL: data types .

And I have this (file from MS SQL database):

Answer 2

Can't figure out what you've come up with?
Databases store a binary representation of data, depending on their type. No one will recode, for example, numbers into a HEX string, this makes no sense.

Answer 3

How did you think that you got "twice as much"?
Fhex = 15dec, for example. Instead of one byte, the decimal representation of the same number would take up two.
Didn't they teach you computer science at school or did you skip it?