Problem/Justification
The usage of the word “usage” on that dashboard display is incorrect. The word “usage” is used when one talks about how something is employed, in order to achieve its purpose. A better word would be “utilization.”
Impact
The GUI would employ improved English language
User Story
The correct usage of words in the English language is important to a good and meaningful user interface
This is the greatest utilization of the forum’s feature request feature.
I will give you complete access to the usage of my vote.
I think the word “usage” here is used to keep the wording consistent with other parts of Linux/Unix. See this for example:
This is just a guess not a defence.
We’ll be the change all of Linux deserves!
Just out of curiosity: Would the 2a definition fit here in your opinion? Seeing as there is an amount mentioned.
“Mommy, what happened in 2026?”
“Child, eighty-five years ago a few brave warriors risked everything to bring proper English grammar to the Linux development ecosystem. Now hurry up and finish breakfast or else you’ll miss your unobatanium-powered rocket school bus.”
Would this mean that I’d have to sudo apt upgrade English_proper periodically? Or should I run the following in bash:
Upgrade the “Proper English” package using administrator privileges.
**I hope OP doesn’t mind a bit of jokes; I swear I voted for your feature request because I oddly agree with it - I’m just having some fun.
Careful! Those commands set everything to EN_GB and make your system have tea time 
The OP does take it as good-hearted humor and teasing. The Linux command line is not even close to half as forgiving as I, when it comes to incorrect expression.
Like I said, the currently common wrong usage of the words “usage” and “use” is a pet peeve of mine. So are using the past tense form of an irregular verb in place of the proper perfect participle, which has crept into common American English parlance over the last couple of years: “I had went to the store.” Or the lack of use of the objective case of a personal pronoun: “When he saw my wife and I.”
I like the structure of language, which has a very similar technicality to it as does technology. I enjoy both.
I looked at it and had to think. I am a language nerd. I still think that the 2a meaning is one that refers to a general meaning, not a specific one. Correct: “My home’s electricity usage is higher in the summer than in the winter.” Incorrect: “Today’s electricity usage was really high, because it was 100° F (~40° C) outside, and the air conditioning ran full bore.”
I am sure, I could have a heated debate about this with another language nerd.
American English dictionary and rules: “What are people saying and doing? How are they using words and phrases? We must track as much as possible and update what is observed.”
French dictionary and rules: “THIS IS HOW IT IS AND NO PLEBE MAY TOUCH IT!”
Well, one could argue then that if “storage amount” is a correct usage of “amount” and we assume the definition of the word “usage” by Webster to be correct, that in this particular case - talking about storage amounts - “usage” is correct here. If one would be a (language) nerd or pedantic. Not that I am any of those things. Especially not the latter.
I have similar discussions about “wrong” use of language in two languages constantly. I absolutely and whole heartedly agree with you on principle. I’m not sure in this specific case. But I am alright with that.
Except for the following 65 words that are exceptions to the rule - there is no logic to why those specific words, simply memorize all of them else everyone will immediately know you’re not a native speaker 
Or a common TV show error:
Instead of “No I don’t mind”.
Isn’t that not how they usually avoid not making that non-mistake?
