See, e.g.:

https://pubmed.ncbi.nlm.nih.gov/37782190/
“Metformin is a medication used to treat type 2 diabetes by inhibiting hepatic glucose production through adenosine monophosphate-activated protein kinase (AMPK) activation.”

https://pubmed.ncbi.nlm.nih.gov/31693892/
“Our results demonstrate that activation of AMPK by metformin improves mitochondrial respiration and hyperglycemia in obesity.”

https://pubmed.ncbi.nlm.nih.gov/33714781/
“Metformin is an oral antihyperglycemic drug widely used to treat type 2 diabetes mellitus (T2DM), acting via indirect activation of 5′ Adenosine monophosphate-activated Protein Kinase (AMPK).”

https://pubmed.ncbi.nlm.nih.gov/36435271/
“Since the antidiabetic effects of metformin are mostly mediated by the activation of AMPK. . .”

A more potent AMPK activator might be useful, but there’s surely a lot of other stuff going on — secondary targets, pharmacokinetic considerations, etc.

Some other research chemicals are highly specific and potent AMPK activators. Whether or not they’re useful in diabetes, though, appears to still be an open question. One of them, AICAR, has seen some use as an athletic doping agent. Anyway, there’s an interesting review here: https://www.nature.com/articles/emm201616