For me, the idea with an I sentence is not that is a law set in stone but a principle that tends to value owning your shit.
In a conflict being able to say, this is how I feel, this what I perceive has brought it about.
You're a stupid asshole
You never do anything right
You don't love me
Expressing how YOU feel and acknowledging that it is YOUR feeling. Then saying when you did this, I felt X, Y, Z.
To me, it's about personal responsibility. And self-awareness. Seeing your feelings and understanding where they come from. Then, expressing that information as calmly and kindly as you can. It has very little to do with pronouns. :P