My wife's uncle looks at least 15 years older than he is, and had his leg amputated due to complications from Type 2. He took better care of himself than your friend did.
Another good friend nearly died 2.5 years ago. I did an emergency flight to Portland to see him before he passed. This was due to complications from Type 2. Thankfully, he got into the hospital, and they got his kidneys going again, but it's pretty touch and go right now. He can't walk much at all, and can barely get to the bathroom on his own (he couldn't on his own when I visited).
That's not just trying to frighten him. That is what's in his future if he doesn't change things right away.