The possessive apostrophe originated as a mistake or idiosyncrasy, credited to one of two people in the early 1500s depending on who's making the assertion, that became widely adopted.

Possession should be, in static, unchanging, OBJECTIVELY CORRECT DON'T YOU DARE GO CHANGIN IT English, written "peoplees" (or something like that but you get the point).

Merely calling "'" an "apostrophe" was a mistake for over a century, as the word was a well-defined rhetorical term that was later adopted to describe the mark sometime during the mark's slow acceptance.

Grammarly makes people sound like soulless automatons who have been trained to write by similarly soulless and robotic corporate ad copy writers.

Sometimes it seems like half the English language is just Shakespeare or some other writer making up shit that sticks-- and that's awesome.