Your vet is right regarding your bun’s health. The only health risk you avoid by neutering a male is testicular cancer, a cancer that’s uncommon in rabbits until they get very old. There are still reasons why people choose to neuter their male bunnies though:

First of all, if you’re planning to get your bun a friend, both buns must be de-sexed or they’ll have babies and fight.

Second, some male buns, but not all, develop sexually motivated adverse behaviors. Sex is very central to rabbits, because in the wild, they live short lives, and they must make as many babies as they possibly can as soon as they can. For this reason, buns tend to have a high sex drive. That makes them prone to urine spraying (marking territory), pooping outside the box (another way of marking territory), courting behaviors such as becoming obsessed with another household pet or a human (and this obsession can mean being obsessed 24/7).

This is the reason why I had my first male bun neutered, he developed these very bothersome, sexually driven behaviors. They went away 2 weeks after the neuter. But there are people here who have a single, intact male that never shows any adverse behaviors exept perhaps a bit of humping a toy now and then.

It’s very different if you have a girl bunny, they do need to be spayed for health reasons.

Ditto everything Bam said. Neutering doesn’t offer much in health benefits for boys (girls are a different story!), but there are some benefits.