The more I read about the causative factors in T2D the more confused I get.
About the only thing I believe is that some time in the next few decades they will nail down the genetic factors more accurately. That would be a big deal in itself.
As my doctor told me in my first appointment post-diagnosis, speaking to someone who was not officially overweight and had no diabetes symptoms: "Who knows, it may have been genetic factors. It is what it is!"
I appreciated his admission of ignorance, but I dearly hope this situation does not prevail forever, for those countless millions who are at risk of T2D.
Knowing more about the causation would not only comfort people with T2D, more importantly it could help screen people who are at greater risk of developing the disease. At that point, lifestyle modifications (or meds, or whatever) could intervene to slow down or prevent what is currently an almost inevitable progression.