non-invasive continuous blood sugar measurement is mired in patents and technical challenges. Turns out it's really difficult to disambiguate the absorption lines of glucose from other similarly shaped molecules when you're also dealing with untangling skin conductivity, transmissivity, sweat, inflammation etc.
I also think there's no financial incentive from incumbents to develop something like this. Why would abbott develop something that works "forever" if they can milk people buying new sensors every 10~14 days.
There is a major IP holder in the space who is asserting their ownership, so even if they could solve the technical challenges, they might not be able to come to market.