They really should be called different names. The diseases are really not all that similar other than (sometimes) the need to take insulin.

Don't only something like 25% of type 2 diabetics take insulin?

Most people with T2D do not take insulin, it's only useful if your body cannot make a sufficient amount. In my case I have no need for it, the cells became resistant to the effects of insulin. 25% is probably a decent estimate.

Well, 86% of the 14 people they tested this on, anyway.