It seems like you would lose meaning by automatically replacing words, no? Why would you want to censor your internet experience, just because you find someone else's use of language awkward?
Germany didn't have “gendered” language, until it was introduced some years ago. It’s a terrible reading experience and super annoying.
Imagine the sentence: The teachers explain to their pupiles that the managers work only for the shareholders.
it was
Die Lehrer erklärten den Schülern, dass die Manager ausschliesslich für die Anteilhaber arbeiten.
and it became:
Die Lehrer:innen erklärten den Schüler:innen, dass die Manager:innen ausschliesslich für die Anteilhaber:innen arbeiten.
It’s insane.
People use the extension for the same reason people use other content blockers against advertisement, notices banners, social media widgets and so on, namely not to suffer avoidable annoyances.
> you would lose meaning
No meaning is lost that has not been there before.
> someone else's use of language awkward
Most would judge that it's not just awkward, but grating.
It's still the same word, just as generic masculine. Gender speech isn't part of the German language but an add-on with no standardization (that's why there are multiple different approaches). Apart from looking awkward one of the main criticisms is that it hurts the reading flow. Following that point the extension improves the reading experience.