fascism noun

fas· cism | \ ˈfa-ˌshi-zəm also ˈfa-ˌsi- \

Definition of fascism

1 often capitalized : a political philosophy, movement, or regime (such as that of the Fascisti) that exalts nation and often race above the individual and that stands for a centralized autocratic government headed by a dictatorial leader, severe economic and social regimentation, and forcible suppression of opposition

2 : a tendency toward or actual exercise of strong autocratic or dictatorial control

https://www.merriam-webster.com/dictionary/fascism

Does the definition of the 99.9% not fit in with that?

As a glib riposte to your last statement: Truth may not be a matter of upvotes, but language definitely is.

Absolutely. From my reading, it’s being used to describe everyone from anti-government libertarians to rationalists, to nationalists to people who think religion is an important part of civic society. I’d like to point out the complete absurdity of describing those wanting smaller government as fascists, but alas, here we are.

As I said in another comment, it’s become a byword for “person with right wing opinions that I disagree with.”

You primarily come across as someone who hasn't read Eco's influential essay or doesn't want to talk about it and instead makes up various straw man arguments. Eco describes fascism very well, based on personal experience with it and a deep knowledge of its origins and appearances.

Language is not defined by dictionaries and historians. It's defined by how people use it.

If 99.9% of people disagree with you on the meaning of a word, you are wrong. You are the one incapable of communicating your ideas in a way that others can understand.

The opponents of Hitler in Germany during the rise of the Nazi party called Hitler and his party "Fascist". The namesake of Antifa, "Antifaschistische Aktion", was founded in Germany in 1932. To insist that Nazis were not fascists isn't commitment to linguistic accuracy, it's Nazi Apologetics and historical revisionism.