Moldbug (Yarvin), who is intellectually upstream of the tech-authoritarian movement, explicitly claimed the term reactionary and spent so many words strawmanning concerns about fascism he de facto claimed that term as well. And either term is a hell of a lot more accurate than "conservative", which [unfortunately] continues to be in use as an emotional fig leaf over what is actually a radical agenda of destruction.
We could argue over the definition of fascism and which politicians fit it which might be more productive than accusing posters of being depressed.
For the people currently active in politics who espouse heinous policies sometimes (and sometimes not) reminiscent of fascism, then advocate against those policies directly. Using such a vague umbrella term, and one interpreted by many as a distinct cultural shibboleth, isn’t likely to win over the people you need in order to prevail.
Another is we discuss actual policy positions rather than using presumed pejoratives to brand everyone who doesn't agree with us as "literally Hitler!".