That question still has to be answered.
It seems as though, invitro fertilization may have a definite factor. They surmise that the manipulation of eggs, sperm and insertion. Not to mention the artificial stimulation of FSH and other hormones.
So there seems to a preponderance of" born with" caused by outside effects which in effect is caused…
A mobius loop.

Some are definitely genetic. In one study, like in my family you just cant get away from genetics. So again born.
The amount that is caused come a variety of things:
Pancreatic problems, accidents, inoculations that went wrong, Lupus, drug reactions all can create true diabetes.
And now there is a definite differentiation between true diabetes and diabetes: other.
True diabetes is where blood level insulin tests are done and shows either insulin levels that are either present or not present and other blood factors that cooberrate which diabetes a persona may have.
And pre diabetes, borderline and insulin insensitivity.
The last is more common than we think. This is type 2 in most cases, so its often age, disease and factor brought on.

So in answer to your question, they still do