Frankly, I am mystified by why the distinction between it's and its is so hard for people to understand that errors with the use of these words appear everywhere.

IT'S = It is.  It has no other meaning.  It's not a possessive pronoun.  It's not correct to write:  "The dog wagged it's tail" (it is tail?); "What is it's name?" (it is name?); "The football team won it's last four games" (it is last four games?).

ITS = Possessive form of it.  Correct:  The dog wagged its tail; What is its name?; The football team won its last four games.

We do not make other personal pronouns possessive by using 's.  Why should we do that with it?  We do not write I's, you's, we's, or they's, and he's and she's mean, respectively, "he is" and "she is."  IT'S and ITS follow the same principal.

By the way, there is no such word as ITS'.