@Antje77 - I say this only from my kind of dual-state of having been a Type 1 and also Type 2 - but the view of what insulin is and does tends to be a polar opposite - because it is - type 1; not enough and type 2; too much.
The role of reducing blood glucose is life-saving for Type one, but is far from being the most important role that it plays - more than 100 different effects, and critically on every cell in your body. Different effects on different cells.
If you think about the "classic" presentation of diabetics 150 year ago before synthetic insulin, the most crucial aspect was that they were physically wasting away; the body could not hold on to any
energy. Blood (and of course urine) glucose was secondary to losing weight rapidly, running out of energy and quickly dying was the primary condition.
insulin is all about energy regulation.
In the most obvious case of chronically elevated insulin, different cells will develop a "too much of a good thing, need more to have the same result" building up of insulin resistance, but because of the hugely complex and interacting nature of insulin, where it can be both cause and effect, you can become insulin resistant for lots of reasons that have nothing to do with food - like getting pregnant (the most striking example).
For the vast majority of T1 - you usually are never in a state of chronic high insulin, you are in total control of what you inject, and the active life of that insulin is finite - you are not generating any from non-food stimulus like Cortisol.
But - the other way to think about it is that with perfect control of your dosing, you can only be close to what the functioning pancreas would deliver - ie, just like everyone else; and depending on the food you eat, your level of needed insulin may be high enough chronically to develop insulin resistance. Just like everyone else.
To address the insulin resistant
liver question - that's easy (indeed that is right in my wheelhouse) - because what is foie gras? - it's a goose with a very insulin resistant liver. A goose with a very fat liver, too; but
not a fat goose. How do you achieve this? - by feeding that goose with lots of high fructose corn syrup in the last weeks of it's life. Why ? because the liver must metabolise fructose. The liver turns that fructose into fat, which it must store itself. When that happens, the liver cells swell up, causing internal inflammation, and resistance to the insulin (which is causing that fat to be stored in the first place). Thus - insulin resistant liver.
All of that can happen without ever seeing a change in blood glucose, because glucose is never involved... This is the particularly insidious thing about fructose.