Word/Phrase to describe someone who wants ALL or NOTHING of it?

I think you are describing a perfectionist:

• somenone with the propensity for being displeased with anything that is not perfect or does not meet extremely high standards.

(AHD)

Consider Completionist

n. (in a video game) a player who attempts to complete every challenge and earn every achievement or trophy

I’m not really a completionist, so I skipped the side missions and focused on the main story quests.

Or try Completist

n. a person who attempts to complete a collection or set, especially a collector who wants to collect an example of every item in a particular field

This recording is a must for obsessive Sinatra completists.

I'd only recommend this movie to Hepburn completists.

Consider, hardnose

hard-nosed adj.

: being tough, stubborn, or uncomprising M-W

hardnose noun

A hard-nosed person M-W

Quiz: Are you a hard-nosed negotiator or a soft touch? British Council

Although it is rarely used the word you are looking for is Absolutist. noun 1. the principle or the exercise of complete and unrestricted power in government. 2. any theory holding that values, principles, etc., are absolute and not relative, dependent, or changeable.