The primary problem with those types of treatments is you have to be on immunosuppressants, or the immune system just kills the cells again. That type of treatment is typically not recommended unless the patient is already on immunosuppressants, or has extreme hypoglycemia unawareness, or extreme needle phobia. Immunosuppressants are typically considered a worse outcome than properly treating T1D with insulin + CGM.
For the same reason, sometimes T1D's will get a pancreas transplant if they are also getting another required transplant that will require immunosuppressants.
I think the best hope in the next 50-100 years or so is continued development and improvement of closed loop systems. Eventually we should get to a point where highly sophisticated closed loop artificial pancreases can automate much of the process away. This will improve treatment and long term health outcomes, but will still require a fairly significant level of maintenance and oversight on the part of the patient (or their parent). There's a lot of really promising work being done there.
If you have the knowledge, I can highly recommend doing some research and try looping. I've been doing it now for three years. Time in range is about 92%, A1c always 5.8-6.0%. 80% of the stress is gone. Life is better.
But, it's not accepted therapy and you have to do lots of research to learn how to use the systems. For me it has worked like nothing else. I got my life back after 21 years of suffering with T1D.
I thought pump implants already did that, what's missing?
Closed loop artificial pancreases are the future, but they will still require a large amount of attention and management by the patient.
My friend got a new high-end closed loop system, and it's so much better than the previous pump. There's still a long way to go before it's truly an artificial pancreas, but my friend already has much higher quality of life, and the tech is still improving.