I'll be upfront about something. I don't know anything. Any opinion I have is based on an incomplete model of the world I live in and as such most likely flawed. That being said, I believe writing down my thoughts helps me solidify my thoughts so here I go:
My thoughts on "form follows function" is to say that form and function go hand in hand. It was never the intention to say that any form is bad form but that the form should not get in the way of function. My understanding of form follows function is that the function is half step ahead of form and should shape form not the other way round. Of course, in a stateful world, we often face a chicken and egg problem. How did our beliefs influence church architecture over the centuries? How much of our church architecture influenced our beliefs over the centuries? We could ask the same about any tool and any behavior. How did the advent of git influence software programming? How did the way we do software programming influence the development of git?
You could say this is a wishy-washy answer or a non-answer but that's all I have at the moment.