You know, we get accused of changing our doctrine or rejecting what previous leaders have said. Even when we explain that an individual teaching doesn't constitute doctrine, people will say "Oh you taught it in the past."
Is it fair to say the Christian Church taught modalism?
LDS folks, I love you, and I know how much you hate it when people mock the temple, get exhalation wrong, or a whole host of other things incorrect.
It is exhausting when you do the same for something you clearly don't understand, nor make an attempt to understand.
This is called modalism, and has been considered heretical for a very long time. The Trinity was not some spur of the moment thing. It was fiercely debated, fought over, and discussed for hundreds of years.
If you want to critique the Trinity, at the very least make an attempt to understand it, why it is, and how it came about before starting to attempt to critique it.