This one troubled me for years - even as a native English speaker. Logically if "John's" means "belonging to John", then "it's" (so it seemed) should mean "belonging to it."
In fact, we don't say "him's". "Its" is a word like "his" - and has no apostrophe.
But, I think John is Fred is trying to start a conversation about complaining about the autocorrect on his device.
English has a collision between possessive apostrophe-S (belonging to it) and contraction apostrophe-S (it is/has/was). For the word "it", somehow English picked the contraction form to have the apostrophe.
La angla enhavas kolizion inter poseda-apostrofa-S (ĝi-a) kaj mallongiga-apostofa-S (ĝi-estas/estis/estos). Por la vorto "it", la angla ial elektis, ke la mallongiga formo havu la apostrofon.