Hasn't the establishment been non-conservatuve at least half of the time for the past 20 years?

In which countries? Most have major parties that are conservative and conservative-light.

I've occasionally seen right-libertarian ones (I think historically this has been the most common form of right-wing-ism in hacker-y spaces).

In general I agree, left-leaning ones are way more common. Maybe you are correct regarding the reasons. But I've definitely seen conservative ones too, with libertarian ones being more common among those (e.g., saw a number of "Who is John Galt?" stickers some years ago).

"Libertarian" and "Conservative" are not inherently linked, even though sadly they're often associated. There are many left-libertarians.

As they mentioned, though, right-wing bumper stickers absolutely are a thing in some places.

Semantic drift.

Why indeed? Why is this something people now have to care about again? https://www.realtimefascism.com/

Because of that keyword, "was." The conservative stance has shifted to become more aligned with fascism.