This was just my understanding from seeing my grand-father 40 years ago having to drop his pants to use insulin syringe + needle, to the use today where you can lift your shirt and use a insulin pen in a couple of seconds.
The infection risk is real. What's the relative risk increase regarding death with (with, not from) Hepatitis B infection (not diagnosis, infection) between people who've never injected themselves with anything and injection drug users?
What is this belief founded upon?
Disposable syringes and detachable needles have been around for over 50 years. We had 6mm needles in the 80s.
Evolution of Insulin Delivery Devices https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7261311/