Why cant insulin be main control?

I'm new to insulin and keep coming across the term insulin resistant, how does one know if they are insulin resistant?

 

You'd usually get your fasting insulin levels tested alongside fasting glucose and your level of insulin resistance could be calculated from that. Unfortunately you stand about zero chance of getting it done via the NHS.
Has your c-peptide ever been tested (sorry if you have been asked this before)?

 

T2 is pretty much synonymous with pathological insulin resistance and hyperinsulinemia. Even someone who has advanced to the stages of insulin deficiency will still be resistant to whatever they still make or eventually end up injecting.

Nothing can be certain without proper testing, but in the absence of this I think anyone with T2 can reasonably assume they are insulin resistant to a fairly large degree. The fact that the NHS still continues to ignore the value of these tests remains my biggest bone of contention with the standard of care. It’s preposterous, putting it politely.