It’s a shame they’re inherently dangerous, hence why they aren’t used anymore. They have a high risk of spreading infection when blood/fluid ricochets back into the device while administering a dose. Thus contaminating the next one to be administered. Basically, the risk isn’t worth the convenience.

I still think they’re pretty cool. They’re the real life inspiration for Star Trek’s hypospray. Many people would love a device like this since fear of needles is quite common.

One colleague of mine has a huge fear of needles. She basically had to be held down by four people while getting her covid shot. It was necessary, she consented to the manhandling… but a device like this would’ve made it a lot less stressful for her to get the shot.