I depend on a pump and CGM (currently that's a Dexcom G7 and Omnipod, but I've used other brands as well).

I like the technology, but you have to 1) know your own body and 2) verify if you are uncertain about the readings. Every time I've switched devices I've interacted with diabetes educators, and they pretty much always tell me to always be prepared to verify manually (with an old-school finger stick and test strips).

Additionally, it's not always the fault of the technology, but often where meatspace and technology interface. When you insert a CGM, there's always a risk of the canula not going into the skin correctly. (usually it's a spring-loaded insertion tool and shoot a needle into your skin quickly, but it can mess up if the amount of pressure applied is wrong etc) In such a case, the sensor that measures your blood will often, where you can't see, sit on top of the skin. This results in insanely low readings. That happens to me a few times a year (I swap out the sensor every 10 days), and you have to listen to how your body feels relative to the readings, and replace the sensor if necessary.