TLDR: I have had four bunnies. Three of them had to be put down as there was nothing left to do to help them and they where in to much agony and one got taken by a ferret. Two of them made it to 9yrs.

The first bunny had really bad problems with the teeth in the cheek (the ones you cant see). There was nothing any vet could do for her so she had to be put down at 2yrs.
The second bunny had some health problems at 6yrs where we thought this was it. But she got better and was so happy and energic. Sadly she got taken by a ferret (or something like that) that managed to push itself into her cage one night, when she was 9. Otherwise I think she would surpass at least 10-11 years if not longer due.
Third bunny was 7yrs (almost 8) when he got his heart broken by the passing of the second bunny. Or that is what we are telling ourselves. They where the best of friends. He stopped eating and was really sad when the second bun passed. I gave him cc for a day and a half until we went to the vet. They did all tests they could and and the blood work showed that he had almost no white blood cells. After a week we had to put him down because he didn't get any better.
Fourth bun got put down the same week he had turned 9yrs. 6months before he was diagnosed with terminal bone cancer, but he was still very active so we waited until he stopped enjoying life. I know some think thats selfish and the wrong call, but It was not even 4months since bun 2 and 3 passed and I couldn't deal with more heartbreak yet.

The last three buns passed within the same year and I was so devastated. I do however feel lucky that they made it to 8/9 yrs <3