If you see an apostrophe with a pronoun, it must be part of a contraction.

its—possessive adjective of it

it’s—contraction for “it is”

We should have never discarded the genitive case.

I don't know about the person who made this picture, but I'm ESL, and this is actually weird phenomenon to me.

Basically when I first was learning the language I had zero problems with it, and never made mistake, but after two decades I noticed I started making those mistakes too.

I still know when to use each and will fix it when reading what I wrote and looking for it, but when I'm just writing I sometimes write incorrectly.

I wonder if it is that I switched from remembering it visually to going by sound or maybe reading text written by other people who also make this mistake.